I have a 350 4bolt main with one piece rear main seal that I plan on cleaning/boring 30 over.When I check out rotating assemblies offered with -5cc,-10cc or -12cc pistons.I'm planning on it being n/a and was thinking of going with the #113 al. heads that I'm putting on the 305 while I get the 355 together.Not sure which assembly to get.TIA

 

Why put the 113's on the 305? Just run what you have and keep them fresh for the new engine.

You may have to slot the two middle intake bolt holes in order to get your lower intake manifold to fit.

How radical do you want the 355 to be? Daily? Weekend? Strip... only then can we give you an educated guess.

 

Since you are at the start of the build, why not ditch the 355 idea, and go 383?

 

It hasn't been my daily driver for over 10 yrs but would like it to be streetable.So to answer the question weekend with occastional strip.And wanna see how much of a improvement the #113's make over the ported stock that I'm running now.

 

Really don't have the extra $ that it takes for the rotating assembly and the machine work plus didn't think TPI & 383 was a good combo

 

355 and 383 is almost identical in cost. The only thing you have to machine is when you install the crank install the piston and rod one by one and make sure the rod shoulders clear the bottom of the bores. If not then hit it with the die grinder. The cost for the kits are almost the same.

 

Not the kits I've seen at Jegs & Summit.And I don't think the 383 would like 113 heads.

 

i have a 383 TPI and all i can say is HOLY F**K!!!! it's a friggin torque monster!! awesome motor! i have the GM hot cam, 1.6 rockers, speed pro flat top hyperutectic pistons, 9.6:1 compression, eagle forged crank, eagle rods, world products sportsman II heads (72cc combustion chamber). oh yeah full roller motor as well. if you want to know anything else please let me know.

 

Hell Ya, Thats' what I like to hear!!! I am about to purchase a forged 383 short block, I already have Vortec heads capapble of .550 lift. And I plan on matching this combo with the Hot Cam, 1.6 rr's, SDPC intake, Slp 1 3/4 Headers, bigger injectors, and a 2,800 stall converter. With the ported plenum and SLP runners....

I'm hoping to get at least 400 lb. feet to the wheels! I think it all all depends on how accurate the custom chip is burnt accordingly to my combo/setup.

 

sweet dude if you need any help let me know! i remember how excited i was when i was building mine!

 

just tagging onto this thread.. I too am just starting an engine build and I am deciding between a 355 or 383

 

Should really be no trouble deciding, IMO. You are building an engine anyway, why leave all the torque on the table, and go with the 355. Think about it for a minute. Why would anyone build a 355, if they had to buy a crank, or rotating assembly, and automatically give up cubic inches. For the small amount of money more, do the 383. I can guarentee you will wish you had if you do not.

 

the 383 TPI is one nasty motor for sure. follow what i said i have in mine (i listed it above) and i guarantee you will not be dissatisfied! it took me 3 years researching what to put in this motor and it was worth every minute! if anyone would like part numbers i can get you part numbers for most of the parts. pistons, rods, and crank are the only ones i don't think i can come up with but eagle was one of the only companies who make the crank needed for this with a one piece rear main.

 

Good Luck with everyone planning it cause mine just got smashed.Lady blew thru a red light and the IROC is totaled.

 

well I'm in a different boat.. I've recently purchased a rebuilt motor. The motor has already been bored out .030 over and has had a new crank, pistons, lifters, pushrods, bearings, etc installed. Its a roller motor that someone rebuilt with a flat tappet cam and lifters.

However the engine wasn't properly stored which has led to surface rust inside the lifter valley, and I've had to toss the lifters and pushrods due to rust. The cylinders and pistons look mint and new. I've yet to pull off the oil pan and inspect the bottom end of the engine.

So this is where my dilema lies... do I pull it apart, hot tank it, and reassemble it as is, or spend more money yet and stroke it? See from what I've been told and read, this is what I've summized; The difference between a 383 & 355 is about 30 lb/ft of torque. The HP depends on other things (cam, induction, etc). But, if you take a 355 & a 383 essentially there is no difference except the stroke, so there is usually around 25-35 increase in TQ. Minimal difference in HP, but the HP peaks about 500 rpm sooner with the 383.

Now I'm not trying to take anything away from the original poster, I was just tagging on to read the replies and see what peoples opinions are.. because I too am just gathering data and information myself trying to make a calculated and informed decision.

EDIT: damn sorry to hear IROCZ4BD3, you posted as I was typing.

 

yea man sorry about your luck.

let me say this i was originally thinking a 355 but i was talked into a 383 and I'm really really glad i was talked into it! there is no substitute for cubic inches! if you have the cash and the time stroke the motor you won't be sorry!

 

Sorry to hear about your loss.

That is my biggest fear, I have 6k tied up into this car and growing. If I got smacked my world would shatter.

Then again I could start over. So will you. When this addiction starts you cannot stop it. It is scary. I spent countless dollars and for a short while I will be satisfied. Then I get unhappy and I have to upgrade. No matter what someone will always be faster and more skilled than you.

So you move on. It never stops.

I can't wait to see your next project.

 

Won't happen.I bought the IROC new when my daughter was 2 weeks old.It was the only one that she smiled it.Can never replace that.

 

How bad is the wreck?

 

Took off the whole front end,rad is smashed up against the engine and the pass fender is pushed against the tire

 

Same kind of wreck appears to have happend to my dads car before. Its definately replacable, just will take some work.

Onto the 383 vs. 355:

both engines have potential to make power in different area. Remember though, a bore is ALWAYS better then a stroke.

When you stroke an engine, you are increasing piston travel, increasing friction, increasing wear. However, this situation doesnt completely apply to this situation, if you could get 383ci, out of a larger bore then stroke, its better then a larger stroke, then bore.

It is true that a 383 will make more TQ then a 355, but a 355 will rev alot higher and is a more stable set up. Also, when building a 355, you are not going over the stroke the engine was intended for. The TPI system will make a **** load of torque, 355 or 383. A 383 is a somewhat more streetable engine due to the powerband being lower. If you plan on later adding forced induction, or something along those lines, a 355 is better.

Im personally planning to put an LT4 into my iroc, because i would rather have a unique car then super fast car. Put alot of thought into what you want out of the car, and when it will be driven, how it will be driven etc.

Hope this helps.

Sheldon

 

You can fix it. If you are convinced that this car has some sort of sentimental value then the fixing part should be an easy decision. Start bone yarding it for a fender, front clip and hack off a rad support.