370 vs 383 ls1

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Jul 18, 2013 | 03:01 PM

Portcityls1

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370 vs 383 ls1

I'm planning to do a build on my ls1 but don't know if I should do a 370 or a 383 build. I've heard the 370 build is better for boost and Easier on gas mileage is this true?

Jul 18, 2013 | 03:05 PM

batboy

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From: middle of nowhere, Kansas

Don't know about better gas mileage, they are probably both about the same in that regard, but a forged 370 is an ideal boost motor.

Jul 18, 2013 | 04:07 PM

HCI2000SS

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From: Howell & Fenton MI

It just depends on the entire build. I just bought a 370 LQ9 forged shortblock from TMS and i'll be running my PRC 5.3 heads along with a pretty big cam and a 100 shot for now. I'm expecting around 440-460 rwhp n/a

Jul 18, 2013 | 04:40 PM

Beau@SDPC

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You actually can't build a 370ci LS1. 370ci is obtained from a 4.030" bore and 3.622" stroke. Can't take an LS1 block out that far. You would have to start with a 6.0L block. 383ci, for reference, is 3.905" bore and 4" stroke.

That said, smaller cubic inch and shorter stroke is better for boost, thus the reason for many boosted 370ci build. If you plan to boost your 5.7L LS1, I would recommend a 3.905" bore and stock stroke, which would be a 347ci

Jul 18, 2013 | 05:45 PM

dcam503

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From: pdx

I dont know much but I do know that increasing the stroke and then boosting it isn't the highest recommended way about it... I would personally look into finding 6.0l block like beau said.