345 engine: To build or not to build

G

Goodie

New member
Hi. I just found this site.
I'm doing a frame off on my '78 Scout 2 that I've had for about 10 years and I had a question about engine possibilities. I'm either going to totally rebuild the 345 or I was thinking of putting a mopar 360 or 440 in it's place. Will the 727 that IH used bolt up to a mopar block? And if so which one, big or small block?
Or if I build the 345, were can I find all the specs? I plan on bore guaging and snap guaging it myself and only taking it to a machine shop if something's actually out of spec since it ran fine when I parked it except for the oil pressure.
Thanks!
 
The IH 727 application is unique to the breed. Mopar blocks will not bolt directly to IH tf trannies the same as IH blocks will not bolt directly to mopar trannies. It can be accomplished, but some fabbing is required. I can't begin to tell you what exactly is involved, but no doubt others with more knowledge on this subject will chime in. All pertinent IH engine data can be found within the pages of the licensed IH light truck repair manuals which can be purchased from several authorized light line vendors.
 
Goodie, I guess you don't have smog nazis in co like we do in CA!
Like scoutboy said the IH 727 isn't a bolt up for any mopar. You would have to swap the guts from the IH 727 into the case of the mopar trans to use the adapter to bolt up your IH Dana 20 t/case, not a problem if you need to rebuild the trans anyway. Small block and big block mopar transmissions have a different case. Easiest way to go is stay with IH motorvation, this is coming from someone who's always wanted to swap in a 44o! So, go for it:yesnod:
 
Pardon me, but what good would swapping the guts from an IH 727 into a mopar 727 be? The innards are common between the two. It's the outer shell (case) that's different. Monte laurer's lil' pink Scout has a built 440 and mopar 727. His wife races it. It can be done. I'm sure he along with Mike mayben who played a big role in the job could clue you in on all the particulars. Both of them are active members on this forum.
 
Scouttoo we have emissions here, broken down into: pre-82 and post-82. I think it's basically centered around the intro of cats. Any pre 82 rig passes easily and no-one gives a crap what eng mod was done.
I just rebuilt the tf myself and it runs tits, so I'd rather incorporate it! A bunch of people that you come across in the wheelin life tend to consider the 345 kind of a boat anchor but what if I punched it out and multi-port injected it? Shaved heads, you know, the whole 9? It's got good torque, I know. I don't know that much about aftermarket parts support. Here in co I could swap eng and drivetrain no prob, but if there's stuff available for the 345 then I'd be intested in keeping it...
 
Goodie I live in the denver area. Pre and post 82 is an idle or enhanced testing. You might still need cats, I have a 77 and it didn't. It is my understanding that the feds changed the rules around then and at some point IH had to put on cats. Go to air care Colorado
Call one of the independent stations and based off of vin they can tell you if a cat is needed. You still need the basic emission stuff that was originally on the engine, now if you change the whole engine?????

There is machinest off of alameda and federal that did denver school buses (392) when they had them, that's who I used. Another off federal and 50th that was also recommended.

I am sure the guy's here can tell you what is worth it or not as far as mods.
 
goodie said:
hi. I just found this site.
I'm doing a frame off on my '78 Scout 2 that I've had for about 10 years and I had a question about engine possibilities. I'm either going to totally rebuild the 345 or I was thinking of putting a mopar 360 or 440 in it's place. Will the 727 that IH used bolt up to a mopar block? And if so which one, big or small block?
Or if I build the 345, were can I find all the specs? I plan on bore guaging and snap guaging it myself and only taking it to a machine shop if something's actually out of spec since it ran fine when I parked it except for the oil pressure.
Thanks!
Click to expand...

Goodie,
I would definitely go for your plan and freshen it up. Have the valves checked and lapped or redone. If the bores have little wear stick standard iron ring set in don't use a moly of chrome ring set as they will take a long time to wear in to the less than perfect bores. You will need to hone the cylinders and make sure you clean them very well before assembly

I would also recommend having new cam bearings installed and verify the oil hole locations after receiving the engine back.

If you want a bit more performance zero deck the block. After you remove the heads place all of the pistons at tdc one at a time and measure how far the piston is below the deck of the block and record the measurements. Take the smallest measurement and have the machine shop remove that much from both decks. This will give you a modest compression (around 1 point) bump and allow you to run a bigger cam.

If you are interested in this we will recommend a cam. A word of caution: if you don't zero deck do not install a larger than stock cam, it will kill your low rpm performance.
 
Regarding swapping the guts from IH into mopar, with my limited understanding, this is necessary because you need to install the IH output shaft to be able to use the IH adapter so that you can use the IH t/case and keep the stock crossmember and driveshafts. If everything is getting changed including t/case, then never mind. Since goodie's trans is rebuilt and he's not opposed to keeping the 345 that's certainly the easiest, most cost effective way to go. The 345 is no slouch when built right and in stock form performs well.
 
Based on the year for smogging in denver, I smogged my 1978 traveler w/o cats with no problem in d-town. They didn't introduce cats in em until 79 I belive.
 
You must log in or register to reply here.
Back
Top