Barak37

I was wondering if i should bore out the 346ci int my 04 GTO. Does anyone know if I could bore it to 383ci or 402ci on a stock block? And how much would it cost me?

twitchtwice

iTrader: (12)

383 is the biggest you can go before you have to start worrying about having to re-sleeve

ndfrsd6

iTrader: (5)

yup.... you need a 6.0 block to go with a 402

Crowder

iTrader: (6)

you can stroke it to like a 3.9x cant you?

ndfrsd6

iTrader: (5)

i really wouldn't want to push that block to that limit....its safer to get the 6.0 block

12secSS

iTrader: (30)

The LS1 stock bore is 3.899" and can be bored to 3.905", anything more will need to be resleeved. The stroke is only 3.622", but you can add a 4.00" crank and make a 383 (when bored). There are other length cranks, like a 3.90 or so. You can't make a 402 as you would need a 6.0L block for that. It has a 4.00" bore, and adding a 4.00" stroke will yeild a 402.

SLOWblackZ

I just did the calculations on the stock numbers you gave and it came out to 354.8??

12secSS

iTrader: (30)

Your math is off, what numbers did you use? Try this using the stock numbers again (3.899 bore, 3.622 stroke)
http://www.wallaceracing.com/cid.php

Eidt: you must have mistyped the bore and stroke as 3.95" for the bore and 3.62" for the stroke. Then I get 354.8 as well.

Barak37

So i could bore it to a 383ci, but would it be worth it ....or just stay with the stock 346ci block and put heads and cam

scidav87

iTrader: (16)

383's have so much more low-end torque..more cubes you have the more power you can make. I'll be going with a 408 in my 2000 SS

Barak37

How much time and Money do you think it would take

samson_420

iTrader: (1)

And how much power can it potentialy make?

I just wonder.

the_merv

iTrader: (88)

383's can be potent, it's a simple build.
A 402 is simple as well, I would spend the extra money to get an Iron Block, cause you will have to get a Crank, Rods, and Pistons for a 383, so might as well get the 4" Pistons and the Block. That and your Acessories and Cover Plates will bolt right up.

scidav87

iTrader: (16)

texas-speed sells complete 383 short blocks for $3600 you could also get the 6.0 truck motor and make a 408. A 383 rotating assy from eagle is about $1600 and get your block machined and assembled. I would say prolly right around $4,000. Or just get a shortblock for $3600. Powerwise, depends what you do, from 450hp & up. Talk to Texas speed and shops of that nature!!

samson_420

iTrader: (1)

450 on HP sounds decent for the buck.

Weiser878

Also, its more than just "boring" to make it a 383. Takes new Crank and pistons, plus the block work.

You can buy the 402 crank and pistons and a 6.0 block for damn near the same price.

The engine has to come out of the car anyway, so why not do the larger, stronger motor?

vuss2107

6.0 is the go for me also i think while its all out of the bay

SOMbitch

iTrader: (8)

The liner is so thin you can't really "bore" a 346 but it can be "honed" safely .010 which takes it to 3.908..... If you are not worried about an extra 75lbs. up front stroke the 6.0 iron block and be done with it....