304 V8 engine difference

overdrivesteve

overdrivesteve

Member
Hello,

please excuse my ignorance, but I am new to IH trucks, but I'm learning a lot as I read through all the posts on this site.
But I have one question I can't find answered definitively anywhere. There is a 304 engine used in the later amc jeeps - is it basically the same 304 engine used in early 60's IH trucks?
And is there any note-worthy differences between the 304 in my 62 pick-up and other 304 engines used in later IH trucks?

Thanks for your help.

Steve
 
The amc 304 and the IH 304 are two different engines. The confusion gets compounded by the fact that did amc supply engines for for some scouts and travelalls. Here's the breakdown:

4 cylinder engines (152/196) were built by IH.
Early 6 cylinder engines (blue diamond, red diamond, etc) were also IH.
Later 6 cylinder engines (Scout iis) had amcs (same as the jeeps of the era).
266, 304, 345, and 392 v8s were all IH sourced engines.
Finally, amc provided 401 v8s for a short time as an option in full size platforms.

Then there's the transmission conversation. The later automatics were sourced from chrysler. They were tf727s built to IH specs with IH-specific bell housings. Contrary to popular rumors, one cannot simply drop a mopar engine into a Scout with a 727. One would have to use the correct mopar 727 and then the proper mopar/IH tail housing to mate to the xfr case.

Clear as mud, right?
 
That's one of the most common misconceptions out there, so don't feel bad. The easy rule of thumb when dealing with internationals is...if the valve cover(s) has "International" on it, International built that engine. No amc v8 engine was ever offered as a Scout power plant.
 
Robert kenney said:
the 401 (stated above) was offered for a short time and it is an amc built mill. Iirc a shortage of 392's made the use of the 401 necessary... A strike?
Yes clear as mud. :confused5:
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Don't make me come down there and slap you Robert! I said Scout power plant, not pickall. Reading is fundamental.:dita:
 
Hello and thank you all for the replies. It's clear to me now ... I think.... ;)

in an unrelated question, if I May, in a truck like mine with a standard trans and divorced transfer case, will any 2wd IH manual trans bolt up directly, including any t34, t35 or t36 I find at a local wrecking yard?
Sorry if this question doesn't exactly belong here, but I'm learning.

Also, how would you generally rate the 304 in terms of durability, dependability, long lasting and economical-to-dive? I do intend to use this truck as a long-distance camper. (that's why I'm thinking in terms of overdrive trans swap) it starts right up and doesn't smoke, even when started cold, but I also know this is not the original engine in this truck.

This, my first IH truck, is expected to arrive later next week. I'm like a kid the day before Christmas. I've restored Chevy trucks in the past, but this is my first IH.

Thanks again everyone.

Steve
 
overdrivesteve said:
hello and thank you all for the replies. It's clear to me now ... I think.... ;)

in an unrelated question, if I May, in a truck like mine with a standard trans and divorced transfer case, will any 2wd IH manual trans bolt up directly, including any t34, t35 or t36 I find at a local wrecking yard?
Sorry if this question doesn't exactly belong here, but I'm learning.

Also, how would you generally rate the 304 in terms of durability, dependability, long lasting and economical-to-dive? I do intend to use this truck as a long-distance camper. (that's why I'm thinking in terms of overdrive trans swap) it starts right up and doesn't smoke, even when started cold, but I also know this is not the original engine in this truck.

This, my first IH truck, is expected to arrive later next week. I'm like a kid the day before Christmas. I've restored Chevy trucks in the past, but this is my first IH.

Thanks again everyone.

Steve
Click to expand...

Steve, no worries about your questions. That's what this forum exists for. My basic primer on the IH sv8 engine family 266-304-345-392 is this...they are slow revving, asthmatic breathing, modest horsepower, appealing flat torque curve, extremely durable, gas suckin' pigs, but they do run real purdy.:ihih: a great many of these engines provided reliable service in prime mover vehicles. They are over-engineered to the point of resembling a diesel engine in many ways. They were built to log 250k plus miles with regular routine maintenance and continuous duty cycles at or near the maximum engine speed of approximately 4k rpms. No mass-produced chryfordrolet of that era could even dream of hitting that longevity and durability Mark under similar strain. The problem is, proper maintenance went out the window 20 years ago on most of the remaining runners. But, if you're fortunate enough to have a decent runner with good compression, solid oil pressure, and doesn't burn too much oil, you can expect a handful of useful years out of it yet. Fuel economy is definitely not a strong suite of these engines. However, stop and think about what kind of real world economy you could realize from a v8 powered offering from any of the other makes of that era. They all sucked down the go-joos. As for your manual transmission questions, I'm not able to get real specific with you there other than to say that there are some avenues available to you. I'm more of a torqueflite auto guy.


Robert kenney said:
your tough man...... I did include the :confused5: meaning that I May or May not be literate. :ciappa:

my reading comprehension is slipping with age... :icon_gonk:
Click to expand...

Just some tuff luvin' for ya buddy! I don't think I've ever had the opportunity to bust your balls before this. It was just too sweet and easy for me to pass up. I won't kick ya to the curb jest yet. You still come in handy around here every great once in awhile!:ciappa:
 
differences between the 304 in my 62 pick-up and other 304 engines used in later IH trucks?
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There are some minor differences. 1967 was when the "e" suffix engines came out. It was a change in the heads that went from quench to squish combustion chambers to reduce emissions, and the corresponding pistons are known as "flat top" pistons. Power is still good. 1973 or 74 the "a" suffix engines were offered. They had less manufacturing and were more for the light duty platforms; they're still tough but didn't have the hardened crank journals or valve rotators like their truck destined brothers. The valve rotators were later included again.

Overall you can not find a tougher engine; provided it gets reasonable care and maintenance. My 266 has had a rough previous owner, piston slap, part of the block broke off and it's been great for the 10 years I've had it. Of course I do take care of it. Economy I wouldn't say is bad for what they do. My 266 used to average 15mpg before e10, now it's about 13/14 mpg. The 345 with a 275 cfm carburetor now gets about 12 to 13 mpg and it seems to haul pretty good in the 71 1210 pickup

will any 2wd IH manual trans bolt up directly, including any t34, t35 or t36 I find at a local wrecking yard?
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Simple answer is no on the t34,35,36. They take a different bell housing. They are a bit longer so the mounts will shift and the intermediate driveline will probably need shortened. They are also quite a bit heavier; I believe about 200# vs 145/150# for a 4 speed. The shifter position is different so some minor sheet metal mods will need done to the cover in the cab. It is totally doable without major re-work or cutting. IH 4spds are interchangeable.

Seeing that you are going to have a camper, you might find that the t34 with the od has quite a jump from 3rd to 4th and that might hurt on a grade if you're hauling some weight; sort of topping out in 3rd or lugging in 4th what do ya do? At least that's how I hear it from some who have one.

The only economic advantage I see with od is the less rpm's the engine has to turn. Not in my experience have I seen fuel saving enough to pay for one. Mpg is pretty much related to throttle angle, depending on engine size. Whether you get power at 2,900 rpm or 1,900 rpm; it's throttle angle that determines how fast the gauge needle moves to e.
 
I see there May have been some clear mud here also. I see the question being with respect to the 304 only and not the truck as such.

When discussing the International sv series of engines, they all have the same bellhousing bolt patern and will accept any gear box that was originaly on a sv v8... Not so when the gear box backed a IH or amc 6. They will be different...

Now when you combine a particular vehical you need to look at the mounting to the under carriage too. That is where the curve balls come from.....

Sorry is my cifferi'n skills are messed up. :prrr:
 
Well maybe my cipher'in was off Robert. I took this question:
will any 2wd IH manual trans bolt up directly, including any t34, t35 or t36 I find at a local wrecking yard?
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To mean as in would it be an easy plug 'n play kinda deal.

Yes they'll bolt directly up okay, but there's some changes that need to be made that I only scratched the surface on. I've seen the 5 spd. Bell housing, and it is different casting wise. The clutch lash-up was different than what I see in a 4 spd. Bell; is what stuck out in my mind
 
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Hi,

I'm happy to hear about the durability of the engine. An engine rebuild was not in my budget at this time. I don't see any seeping or dripping anywhere and no exhaust smoke at all. But do they all have a very low oil pressure, according to the stock dash oil gauge, during idle?

Also, what seems to be the best oil filter brand for these engines?

But now the trans part of the picture has muddied up a little for me. Perhaps let me ask it this way. Can I properly install a bell housing for a 5 speed trans with no modification to the truck?

I can handle the actual trans install, if it bolts up, the clutch adjustment, new hole in the floor for the shifter, and making a custom intermediate drive shaft. Have I left anything out, other than a little cussing and bloodied knuckles?

Thanks.

Steve
 
Normal oil pressure for these engines is lower than what you are used to from the big3, especially at hot idle. The IH engine lubrication system is more about volume than pressure. That said, there are still minimum benchmarks. Firstly, after all these eons, your factory op sender, wiring terminals, and instruments are not to be trusted blindly. At the least, I would install a temporary wet gauge in conjunction with your next lof to see some meaningful numbers under various operating conditions as they relate to what your factory gauge is saying.
For the filter, avoid fram at all costs. They are the worst piles o'crap money can buy. Quality choices include wix, baldwin, hastings, purolator, and partsmaster (a low $ option made by wix). As for oil, your top shelf choice is the swepco brand available through ihon. As an independent company, they are able to offer a much more pure product with all the zddp that our old, flat tappet engines need to stave off premature camshaft and lifter wear. Commercially available oils don't offer this vital protection any longer and haven't for the past 5 years. So you wind up needing to grab some bottle of zinc additive and playing driveway chemist in the hopes of restoring that critical protection barrier. There's expense involved in a proper oil change for any pre-'97 produced engine no matter how you approach it. The question boils down to how much hassle is it worth to maybe save a ten-spot when all is said and done. Whatever you decide, take your local climate and basic temperature for the next 3 to 6 months into consideration. If sub-freezing temps are commonplace, go with a 15w-40 for now. If temps tend towards the milder side, you can run a 20w-50 year round. Finally, some op numbers: at cold start, you should see close to 50 psi. At hot idle, you should see @ 10 psi. While cruising around, a minimum of 10 psi per thousand revs is acceptable for these engines. Spend some time buklarnin' yersef up guuder by eyeballin' thru the stickied threads awthurd by Mike mayben in this here sub-section regarding the intrikuhseez uh how these motors git theyselves lubrikatid and the common problems associated within.
 
Wow, what a lot of incredible information has been posted in this thread! Thank you all!

Somewhere in one of the other threads I read where some engines, if used in a loadstar, have a bigger oil filter. Is this larger oil filter interchangeable with the smaller filter used on this engine? Another related question would be if the oil is changed regularly, is there any advantage to using this larger oil filter?
Do you happen to have a standard wix or purolator oil filter part number handy? I just want to be sure I start off right.

My next question is the use of gas filters. It appears my truck has some type of glass filter attached to the fuel pump. (I did not get a good view of it at the time of inspection, and my truck has not arrived yet). Is this filter replaceable, and what filters there do you recommend? Any part numbers handy?

On a related note, ac made (and probably still does) a small glass bowl fuel filter that would attach at the carb fuel line input. The purpose was to finely filter the fuel and separate any water from the fuel. What is now considered the best possible visible fuel filter add-on unit? Is it still this little ac filter unit?

Another question (I hope you don't mind) I believe my truck has the original radiator, although it has been rebuilt at some point in the recent past. What pressure and brand radiator cap is recommended? Also, I would like to add an over-flow reservoir. What radiator cap do you recommend where as the engine cools the coolant will be sucked back into the radiator? Any part numbers handy? In the past, I've found most radiator caps sold at the local parts stores don't do this and I've had to go to the dealership for an original cap.

Thank you all again!

Steve
 
To my knowledge, the loadstar oil filter is taller from top to bottom which accounts for the added capacity, but beyond that it is interchangeable with the normal filter. You'd want to look for clearance issues. Advantageous? Maybe, but the standard capacity has proven to be more than adequate in light truck applications for decades. As for part numbers on the normal filters, here's a handy trick to tuck away for future reference. Ford v8 engines from the 60's up into the 90's use the same filter. So if your counter clown can't comprehend ihc, or the filter catalog/pooter doesn't have ihc listed, just look up Ford 5.0/302 or 5.8/351 etc and that will get you what you need.

The fuel pump you describe is the early version with a glass sediment bowl, which is a nice feature. Cost reduction over the years is the primary reason why that style isn't commonplace anymore. I don't know if there is a source for new replacements of those. The new pumps that I know of don't have the sediment bowl. With today's crapball ethanol blend fuels, adequate filtration is more important than ever. It is not a bad idea to have a filter between the tank and the pump, and also one between the pump and the carb. Use glass or metal around the engine.

For your older, upright radiator, I would not exceed a 7lb pressure cap. I like the stant lev-r-vent. You can take your current one with you for comparison at purchase time to get the right fit. Most auto parts stores have generic burp bottle options available, or if you like hitting the u-pullits, you can grab just about anything your heart desires that isn't rotten.
 
304 in my 62 pick-up
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If it's a spin-on filter, a purolater l3001 will be just right. Some trucks of that era had a canister style that it would be best to take the cartridge to a parts house and show them the cartridge and hopefully the number is still readable.

The fuel pump bowl filter will usually take a napa 3002 fuel filter. It comes with gaskets, but you usually have to modify one to fit right.

With old trucks and e10, a double filter system is a a good way to go so an inline filter before the carb is a very good idea. Keep it away from engine heat as much as possible. If you plan on only an occasional drive with the truck, treat the fuel with stabil marine grade fuel additive, it really does help.
 
Everyone, your help is really appreciated.

I just came back from a major car show here in los angeles. There were hundreds of cars, and trucks, and some jeeps and vintage military vehicles, vans and panel trucks. There were also some incredible one-of-a-kind creations. Many vehicles were fully restored and some were in various stages of repair.
But not one IH of any kind was represented!

No wonder IH trucks are new to me. And no wonder I get the deer-in-headlights reaction when I try to tell people about my truck. But the better informed have asked me what I'm going to do with an old semi truck. It seems like no one in a city like los angeles has a clue about the products, or can appreciate the heritage and contributions a company like International Harvester has made to the growth of this country.

So thank you again everyone. Without your help my truck would become just one more rust-Mark in the history books of past vehicle endeavours .

Steve
 
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