jak2908

what do people have out there? what is preferred? what are the pros and cons of each? thanks!

Apeiron

What are you calling "old" and "new"?

3rdgenmaro

iTrader: (9)

If you are talking
old= 400 crank and rods into a 350
new= 383 specific new crank and rods

then definately go new. The old style used very short rods. They dont hold up as well.

jak2908

ya thats exactly what im talkin about

AlkyIROC

When I bought my car, it had a high mileage old school 383 in it. Cast 400 crank. 400 rods and rod bolts, cast 350 pistons. It had a nice solid cam but poor smog heads. The first year I raced it, I managed a best of 14.0. After the first season, I yanked off the heads and put some big valve, highly ported camel heads on the engine and swapped out the 700R4 for a TH350 with a 3800 stall converter. First pass of the second season, I ran 12.0 and everyone wanted to know where I hid the NOS bottle. I managed a very high 11 by the end of the season and on the last race day of the second season, the engine let go. I don't know if a rod bolt failed or a piston disintegrated. I yanked the intake and heads off and threw the rest in the scrap metal. The heads had 5 visibly bent valves to give you an idea on how much damage was done.

I managed 200 1/4 mile passes with the engine and know the engine was in at least 3 other cars before being put into the Camaro. It's hard to know exactly what failed but I was also spinning it to 7000 rpm and near the end of the second season, I was using a 2-step.

A "new school" 383 with better parts would probably have survived a lot longer but would also have cost a lot more to build. If you do manage to find a 400 engine to use the crank and rods to make a 383, it would be much better to just build the 400. For a typical street car with limited or no track time, there's nothing wrong with building an old school 383 for nothing more than some machine shop work. The mains on the 400 crank need to be turned down to fit in the 350 block then the block needs to be bored .030" over. Oversize cast pistons are cheap. If the 350 has already been bored out, it's just a matter of changing the crank and rods.

jak2908

that sounds pretty good..i'd like to atleast run 6500 with it..what were you using for a cam? and would some vortec heads be decent?

LilJayV10

iTrader: (5)

The vortec heads would work but are going to limit your airflow. I think they are around 170cc. It just depends on how high you are going to spin and how big of cam you have.

AlkyIROC

I can't remember the exact cam. Could have been Crane or CC. It was a solid flat tappet with around .550 lift. I can't remember any more specs since that was almost 10 years ago. The cam number might still be on my car's web page.

five7kid

iTrader: (14)

Sounds old-school to me.

New school would be a stroked LS1.