SELLSZ06

iTrader: (12)

I wanted you guys to help me pick out my new shortblock. My objectives are: aluminum block, to work well with my GT42, HiFlo hot parts(if they ever send it to me), ls6 cam with a go anywhere-anytime on pump gas. Saving money is always a plus, but if Iam going to do it I will do it right. Iam considering a 347, 370 or even a 402 all aluminum, they cost around $3000/3700/4200, but the ls2's need another $500 for ls2 to ls1 conversion. My main questions are:
-will a 402 be too big for my GT42?
-do bigger engines make more heat?
-what will be power difference?

Help me out what do you guys think?

Boostaholic

iTrader: (4)

I would choose a 402ci for sure, try to shoot for 8.3-8.5:1 with a stock thickness MLS head gasket, and are you just oging with the Z06 cam to save some cash?

Also get head, and main studs when you do your short block, you may also consider that new high volume oil pump that thunder has, I've been wanting to try it myself and its pretty cheap for what it is.

SELLSZ06

iTrader: (12)

I have the ls6 cam already, and I like it its stealthy. I think it will be a 370 8.5 comp. for budget, hey any idea about the power difference?

52172

iTrader: (2)

not enough to worry you will see plenty of power on the 370 and if you want more just up the boost.

SVT THIS

iTrader: (27)

408 iron for budget. It should run damn near the same price wise as a 370.

BIG BAD BLACKSS

iTrader: (4)

370, unless you wanna run a HUGE (88+) turbo dont go for a 400+ cube motor. Look at the fastest cars that are still drivable, a great majority are doing it with 346-370's, theres a few 400+ in the mix but not as many. Everyone always screams big cubes BIG CUBES, you gotta have BIG CUBES! But remember you have to FEED those hungry cubes! I was on the fence a long time and kept hearinga bout people building these big bad big cube motors, but when i looked at what the fast guys had, they usually werent these huge cube motors. (not talking about the realllllly crazy big cube motors, but i dont think youw ant to get that crazy and run 8s and whatnot here).

Hell speed inc made 995 RWHP on their lil 370 with a 88mm turbo and tehy drive it to all kindsa car shows. Its completely streetable. Why throw $ at big cubes and a bigger turbo when you can accomplish your goals for much less $. BIg cubes are great for bragging, but you dont necessarily need em to go fast when forced inductions thrown into the mix.

SELLSZ06

iTrader: (12)

SVT THIS: I considered iron but Iam sticking with aluminum block for less weight.

I hear what you guys are saying and I agree with you, Iam going with a 370 or a 347 b/c of the price. I figure a 370 will cost me $1200 more than the 347, is it worth the extra power Ill get from the extra cubes? I know that any turbo ls1 will make insane power, so is just a matter of finding the balance of price and performance.

52172

iTrader: (2)

go forged 346 and you will have spent the least amount of money and will still have more power than you will need.

67Firebird455

iTrader: (27)

That's what I decided on, I was originally going to build a 383, then i decided 408, then I eventually decided I could just turn up the boost if I wanted to and call it done. It's already going to be enough power for a street car. Another vote for a 347.

SELLSZ06

iTrader: (12)

I should do the 347 and with the left over money I should get the Edelbrock intake.

bboyferal

iTrader: (9)

Working on a 8.5:1 CR 346 project here... It was DEFINITELY the cheapest... More power than ever needed like 52172 posted...

mahhddgtp

Forged 346. If I had the money, I'd drop it all on a big cube, boosted motor that could take a beating all day long with pumpgas.... But then again, taht's a lot of money.. Realistically, unless I get rich, I'd go with a forged 346...

It'll make some freakin' power.

Toonz

iTrader: (6)

Another vote for the 346... we just found out the hard way on my little bro's 370 that a GT42 wasn't enough turbo for it, had to upgrade to an 88mm.

King James

iTrader: (13)

After doing some research and talking to some people the GT42 seems too small for a 370 unless your only going to rev the car to 6200 rpms.

bowtieman81

iTrader: (35)

I would go for a 346 or a 364 (ls2 forged shortblock).

Depending on how much of a hurry your in you could maybe go L92 for a little more displacement and still be reasonably cheap.

SELLSZ06

iTrader: (12)

wow, I thought a 370 would be perfect for my GT42, I was wantng the 370 but now Iam 90% going with a 347. Going to give LME a call, WHo else can build me a f/i shortblock. thanks guys

Boostaholic

iTrader: (4)

HPE did mine, they do good work and are helpful on the phone.

SELLSZ06

iTrader: (12)

Ill give them a call too,
I just spoke with Jose he said go w/ 370 for less boost, confused about what to do still. Iam not looking for a race car, I would hate to run out of turbo, but its easier to buy a new turbo than a new engine, so if I max it out...

y2khawk

iTrader: (5)

how much power/boost?

a big garrett wheel 42 won't be happy much past 5500 RPM on low teens for boost. Keep it under 10 and maybe.

DrTurbo

iTrader: (3)

I spoke to Jose about it and he said "pump gas" was the key word. If you want to achieve the most with pump, bigger motor will be the best bet. He said if you were going to use race gas, then stock displacement would have been the better choice......

Guess it depends on what you plan to push this setup to.