mustangmuncher

Okay, decided against cam only, and to do the bottom end with the whole build-up, so everything wears evenly and there is no change with all the pieces. I want to do a 355, and retain the stock crank. Can the stock crank take that many RPM's? I have read that it is a really strong crank, so I imagine it could take the RPM's. I know it is .030 over on the block, but I just don't know which pistons/rods to go with. I will be staying N/A and the cam I plan on using is the GM 847. I plan to port the stock heads decently as well. I want to spin to probably 6800 RPM's. I want it to be a nice street/strip car, that will run in the 12.0's and faster without any power adder. I see that reasonable with that cam and decent heads, as I have read of people running 12.5's and faster with just the 847 cam and unported stock heads. So what rods/pistons would you guys recommend? I just don't know where to go with those. Since it will be a street car as well.. (kind of a daily driver..) no crazy high compression, maybe somewhere near stock maybe a lil higher. Help me out, what sizes and stuff like that. Thanks

-Eric

cmking26

I kept stock crank and rods. My machinist used Mahle brand pistons .030 and he said they are basically a stock type replacement. Kept compression down and good fit. I'm not sure where he ordered them from though. He also said the stock crank is capable of high hp and rpm's.

Eric85

I used the stock crank but i went with new Eagle H beam rods and SRP pistons. I actually bumped the compression down a little bit. And yes my machinist said that LT1s cranks are about the strongest crank from the factory.

12SCNDZ

mid 12's??? Heck, I've been there with just a ported head/CC305 combo...LOL. 12.05@112 MPH, to be exact...With a full weight car that's still emissins legal. The stock bottom end has 96,000 miles on it.

If you notice in my sig, I'm building a similar combination to what you're planning. I'm planning on being somewhere in the mid 11's on motor with the 355. As a reference, a buddy of mine has a 355 with a GTP-6 cam in a 3600# '96 Z that runs 11.4 on motor and 10.35 on a 150 shot. The GTP-6 cam has very similar numbers to the 847. He's using a stock crank and 2 bolt main block in his combination.

I recently posted a question concerning the stock LT1 crank...It seems that nobody has ever broken one From what I gather, these are pretty stout pieces. I'm spending my money on the rods and pistons. I just picked up the rods yesterday, which are 4340 Manley 6" H-Beams, which cost me $540. I'm going with Forged JE "nitrous" pistons that will give me approx. 11.5:1-12:1 compression, which will run me $550. It's not exactly a "budget build", but I plan on shooting this thing with a 200 shot. I kinda like the idea of taking the little 355 stroker hunting

Frank

dmoor88

if you're looking at staying N/A, check out a nice set of Keith Black hypereutectic pistons. this is what I'll be going with on my 355 rebuild. the stock crank, after being prepped and polished, will work just fine for your application.

if you want to make a slight change to your compression you could just go with Impy gaskets instead of stock replacements.