I'm finding the turnkey engines offered by proformanceunlimited.com to be intriguing. Are they a fairly reputable outfit?

Any other places to recommend or I should stay away from?

Actually if I could find a reputable company that makes 400 SBC turnkeys or even long blocks I'd forget about the 383 in a heartbeat. There is no replacement for displacement and everyone seems to own one.

Besides, I'm a little skeptical of them. I think there was a reason Chevy never offered them in a mass produced car.

 

Anyone delt with YearOne engines? I was looking at them, they are decently priced also.

 

i assume you mean the 383? they never offered them because the 383 is not a production engine.. its the bastard son of a 350 block and a 400 crank, a combo the gearheads of the 60-70's i guess, figured out.

i recently bought an engine from T and L engine development in NC, and i found there service to be fantastic and the prices fair. From my dealings with them i would definitely recommend them and would buy from them again in a heart beat. If you want a stroker, either a 383, 396, or 408 smallblock, they make some very nice pieces, and will build whatever you want is you desire something different.

 

Yes I was talking about the 383 and I've done a fair bit of research on them. They caught on in the late eighties in the aftermarket.

And I'm thinking there was a reason they were never offered in a production car. Something just raises a flag when I hear "grind .200 off the crank."

Forgive the skepticism but I want to know exactly what I want before I start and know the advantages and disadvantages of everything I do.

 

Since the 400 didn't come out until the 1970 model year, make that 70-80's.

Rumors are the factory played around with 4" bore/3.75" stroke engines, but never put them into production. Their current crate 383 is a 4" bore/3.80" stroke.

One of the reasons the 383 came about was the propensity of the 400 block to crack. Left guys with good cranks/no blocks, a simple turn-down of the main journals, and you have a stroker for your good 350 block that wiped out the crank.

383's are so common these days, almost doesn't make sense to rebuild a 3.48" stroke 350. Very reliable.

 

your right, the 400's did not come out till the early 70's, oops, i thought that didnt sound right.