built 304/345 price and specs

B

blackscout

New member
Curious on pricing for a 304 or 345 built like what you have shown on your site with the isky cam, headers and carb. Also wondering if you have any idea what kind of power either would put out, or if there is a big difference between a 304 and 345 if they are built similarly. Thanks!
 
I'm sorry, I noticed them on Isa's site. It showed a 304 with #3 isky cam, headers, and the 4 barrel manifold I believe. The 345 in mine is pretty worn out and I'm trying to figure out what would be the easiest and most cost efficient route to go. I'm not looking to build a street racer but I'd like to have decent power and most of my driving is on-road.
 
I had my 345 rebuilt with some signficant porting to the heads. It ran just over 3000. The rebuild kit itself was 900. The exhaust ports in the IH are the choking point. If you undertake a rebuild, you might as well invest the cash in having the machinist open them up.
 
I have not seen any hp and torque charts showing how much these changes will make over stock setup.
Cams tend to push the power curve up the rpm range and your vacuum at idle will be lower. You will get more hp and torque.
Light porting on the heads is a good idea. You can remove the "exhaust hump" to help remove some restrictions. Major porting can be done, but then again it will run better at high rpm's vs low
header's will also allow more flow so when your wfo the engine can breath better. You did not mention intake, but a larger intake will help too.
I went fuel injection as it helps to meter the fuel more efficiently and can really help with altitude changes vs a carb.
I live at 50 feet and wheel at 6,000+ feet

I spent over $1,000 just on machine work, with porting the heads and having the engine balanced. So it's going to cost a lot. I had to spend a couple hundred on new exhaust valves too.

Think of the 345 as a stroked 304, more torque, but the 304 will wind up real fast. The 345 has a little more "seat of the pants" pull, but the 304 are nice as they scream.

You can put a Chevy/Ford/mopar engine in there, but why did you buy the IH? Might as well just jump ship and buy a blazer/Bronco/ram charger to start your project.

304
304graph.gif


345
345graph.gif
 
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