TransAm2002

iTrader: (3)

I am looking into doing a 383 in the near future. Compression will be around 11.4-11.5. I will be using my PRC 5.3 stage 2.5 heads and MS3 cam with this set up. I am also adding a Fast 92. Do you think I will be close to 500 RWHP and 460 RWTQ? Should I go with a bigger cam? Car is a street car that hits the track in the winter. Also will be putting a 200-250 through a Nitrous Dave's plate until I can get a stand alone and direct port set up. Thanks for any replies.

burnout346

iTrader: (1)

I think you should be close to 500rwhp. Your torque should be more than 460. I run a slightly bigger cam and more compression and put down 541.7RWTQ.

cbra-klla

iTrader: (52)

My 383 is almost done. Compression is 13.75 to 1 with a 244 254 cam. I'm more worried about track times though

ssZL402

i think you should consider either a 402 or 408 torque requires cubes and u dont want to max your motor out that fast they make big blocks for a reason

XS HP

I agree brandon. After our conversation the other day, I would say that you should go with a 402 or 408. If you are already spending a few thousand on a new block, might as well take the next step completely and make sure you are well into the 500's.

allngn_c5

iTrader: (3)

As the old addage goes, theres no replacement for displacement.

See sig for some nice tips on daily driveable N/A power. Track times coming soon.

Vindicated346

iTrader: (1)

maybe im reading this wrong or something, but are you referring to a 402 or 408 LSX as a "big block"?

viper,redZ

iTrader: (7)

Ok got a ? to add if I build a 383 aluminum block and it made say 460-500 hp and I built a 402-408 iron block and it made 500-540 hp. Do u really think the 402 car would be that much faster . Yes I know the torque would be different but the 80-100lbs weight difference seems like it would make up the hp/tq difference . Like I said its a ? not an opion

caviness

iTrader: (14)

aluminum 402 no weight difference and 40 or 50hp or tq will make a little difference.

viper,redZ

iTrader: (7)

In that case I understand but how many people can go out and buy and aliuminum 402 ? I saying in the real world iron 408 vs aluminum 383 .

allngn_c5

iTrader: (3)

I'd still take the IRON 408 based on the block strength factor. The iron block will take a lot more then an aluminum based 383. JMHO

viper,redZ

iTrader: (7)

Then why did you build a ls2 ? That kinda contradicted your statement above . I know the iron block will be durable but if u making 500-550 rwhp durability does not come into play imo .

allngn_c5

iTrader: (3)

Not at all. Re Read the question above my comment. He asksed 383 aluminum vs 408 iron. 402 aluminum wasn't a choice. If it was, I would've picked ls2 402. I also believe the poster was referring to using an ls1 aluminum block with a 4 inch crank to make his 383. Aluminum LS2 block strength is greater then the aluminum ls1. I hope that clears up your misunderstanding.

Michael02hawk

iTrader: (26)

I've been running a stroked 383 LS6 block in my Trans AM for 5 years now. I am putting down the EXACT numbers your quoting above!

My compression is right at 11.4!

See my sig/web link for the details of my setup.

TransAm2002

iTrader: (3)

Wow, sounds good. Very nice set up you have.

Michael02hawk

iTrader: (26)

Thanks - I love this car of mine!

It's streetable,
Just loud enough to get attention,
a head turner,
...oh yeah, and Fast!

It's not a sleeper, but people just dont realize what it can do.

...very few that pull up next to me wins (or even tries)....very few.

383lt1impala

iTrader: (33)

I think u will be close. I would go with a custom grind. Hopefully I can hit over 500rwhp. My set up is a
383 ls1 forged bottom end.
12.56 to 1 compression
Good ported 806s.
Victor jr with 4 barrel tb.
Ms4 cam with 112lsa.
I also plan to shoot a 300shot in it. It should make my impala move!!!

SS DNA

iTrader: (7)

Is there any idle videos of your car ?

Johnnystock

iTrader: (6)

Alum 402 is not that much pricier than a iron 408. 500-800$ more at most. and yes I would take an iron 408 before a 383. But thats me

Sigforty

https://ls1tech.com/forums/dynamomet...t-results.html

Sounds like you want to do what I did. Here is my setup if you care to look at some numbers.