Motor in my Impala is coming out this winter. Don't know if I want to stay 355 or build a 383. Car is running good on a 355 with a cast Eagle crank, 5.7 Eagle SIR rods, and SRP flatops. Car is running mid 11's on a 150 shot but don't want to push it much more with the cast crank. I am getting a set of AI 200cc heads to go with the new setup and forging the rotating assembly to add more nitrous. I just don't know if it worth the extra machining and money for a 383. As far as a cam I am going with an AI street solid roller. Would like to put the boat in the 10's but don't if I can on a 355. What do you all think? 355 or 383. Remember the car weighs in at a portly 4400 with me in it.

 

383 is going to give you more options later on, but it's also going to make the build
a little more expensive at the machine shop. Either way, do it right and don't cut corners.
A well-built 355 is better than a 383 done on the cheap anyday (even more so as time goes on)

 

If you can afford to go forged 383 then do it. 355's are good motors and being a solid roller can make a lot of torque to get that thing moving. Ported stock castings on a 355 should be nice, not sure how much air a 383 would need though. I personally don't think you can go wrong either way.

 

I think 200cc heads would be a little small on a 383. If you build a 355 right you can get well into the 10's, especially if you juicing it a little.

 

I was leaning toward a forged 4 bolt slayed 355 by want some ideas from other 355 and 383 people before I make my final decision. I think it would be neater to say I have a 10 sec Impala SS with a 355 than a 383 but if the 383 is better to help get the boat out of the hole then I don't know. Keep the comments coming.

 

You're buying a new crank anyways get the longer arm. The extra machine work of a 383 doesnt amount to spit compared to the total cost, you can even do it at home if you dont suck. Cubic inches = hp/tq, just remember its a 383 when you're picking the parts. Tell you what call up ai and ask them what they think you should do.

If i was doing it again I have no doubts I would do a 383, i am right up on the 7000rpm limits of the stock pcm as it currently sits. I have my old short block in the garage that i'm going to start making into a stroker.

 

check a/i's website under customers cars you can get an idea of different head combos in SRs

a budget 355>budget 383

if you're going aftermarket crank tho I see no reason why not to go 383