lifeisgood

iTrader: (4)

i was wondering what kind of power people are making on the 2 bolt main blocks. how strong/dependable they are.
my last build with an lt1 i had it line honed and prepped with 4 bolt mains....

lifeisgood

iTrader: (4)

no one? lol

jaycenk

iTrader: (1)

I think I read that you are good to like 500 to 600 hp on them but it realy depends on what kind of use the engine is going to see. I have a 383 making 400 to 450 on 2 bolt mains

AChotrod

iTrader: (17)

Mains generally are not the problem, if the motor is correctly balanced. Rod bearings are more prone to go out. With that said its always better to go 4 bolt if you got the extra coin

mean_greenZ

iTrader: (1)

There are lots of people i know of making a good bit of power on stock 2 bolt block.

texas94z

stock crank = 2 bolt
aftermarket crank = splayed 4 bolt

fleetmgr

Why does the crank matter? It won't care if it's held in place with 2 or 4.

Fazz73jr

iTrader: (3)

If its as strong as a gen1 SBC. The general rule is 500+ needs a 4 bolt. Anything less 2 bolt with arp studs will do.

Now with that said I know of a couple guys running 400 SBC 2 bolts pushing close to 600hp. With no problems. Although they have arp studs and main girdles. Another guy I know is probably making 450 HP on a 383 2 bolt with only arp studs. He shoots it with a 150 shot at the track with no problems. Although he's only made about 5 or 6 nitrous passes.

96capricemgr

iTrader: (1)

By pretty much all accounts the LT1 block is better than the gen 1 blocks, designed later with "lessons learned". The fastest NA LT1 Impala going 10.5 at 3800lbs runs 2-bolt. Believe it is up in the 500rwhp neighborhood.

fuel

iTrader: (13)

i was making aroung 800hp at the crank with a 300 shot.....2 bolt main with studs

Purple Poncho

iTrader: (1)

I've made 560 to 600rw with a studded 2 bolt and a cast Scat crank for the past 7 years.
Proper assembly, keeping the revs reasonable and a good tune are key.

draggin97s10

iTrader: (2)

all the guys with badass circle track motors around here run 2bolt mains they or 650 to 750. although they do tear them down whenever need be. i wouldnt be scared to run 500 to 600 on a 2bolt. but thats just my opinion. my 385 is a 4bolt.

lifeisgood

iTrader: (4)

thanks for the info guys, i dont plan on revving this thing past stock shift points. just turboing the engine. and see how it does

suicidal racing

iTrader: (14)

around 750hp ive done with gen1 2 bolt with studs,no filler in the block and stock crank and rods with just arp bolts in them..

im looking to make around 700hp on my stock lt1 crank,rods and pistons now with the stock block.

Gabbiani

iTrader: (20)

560rwhp 640tq - think I made more after that with more boost. Never dynod again. 6k rpm. 2 bolt arp studs.

The bearings still looked perfect but you could see under the caps where they were starting to chatter. Tiny stress cracks etc.

This time it is going together with splayed caps.

RamAir95TA

iTrader: (2)

Surprisingly enough the 2-bolt mains are incredibly strong. I wouldn't worry about it.

Having said that, I found a deal on a 4-bolt block and couldn't pass it up for my 383.