Flow and Runner Spec's for Stock 5.3L Heads

[RedHeartbeat]

He can bump the compression up to about 15:1 and get those numbers.

[PurpleMinivan]

He can bump the compression up to about 15:1 and get those numbers.

I knew someone would come back with that one! I think it would actually have to be a 15.4:1CR

[SS Killer]

I knew someone would come back with that one! I think it would actually have to be a 15.4:1CR

440ci! LS7! Now you're getting expensive.

I'm looking for 750 ft/lb of torque with this set-up. I want to get it real bad and I think I can with the right cam and a real good tune.

I mean, I'm making 350HP on a 5.3L with a cam and LT's. Take a 6.7L with a big ole bumpstick and all the air I can scavenge. I might make it... but, if at first you don't succeed, SUPERCHARGE!

[PurpleMinivan]

440ci! LS7! Now you're getting expensive.

I'm looking for 750 ft/lb of torque with this set-up. I want to get it real bad and I think I can with the right cam and a real good tune.

I mean, I'm making 350HP on a 5.3L with a cam and LT's. 6.7L with a big ole bumpstick and all the air I can scavenge... but, if at first you don't succeed, SUPERCHARGE!

By the time you build that 6.7L to a high compression and NOT EVEN HAVE 650hp/tq... Take it back apart and lower the compression and add the supercharger... You could have just bought a 440 LS7 and had some money left over to put towards a tranny.

[SS Killer]

By the time you build that 6.7L to a high compression and NOT EVEN HAVE 650hp/tq... Take it back apart and lower the compression and add the supercharger... You could have just bought a 440 LS7 and had some money left over to put towards a tranny.

Oh, the tranny's taken care of... it's the next step (before the engine) and will be a stage 4 4L80E from FLT.

You're right... but say I spend 11k on a LS7 instead of 9,600 on a 6.7L and make right at 700 hp but end up wanting more. Putting the SC on a LS7 would require the same amount of work and possibly more expensive parts.

It's a proccess. I'm gonna be happy with an N/A 6.7L I think... but if I'm not, there's always the next step.

[PurpleMinivan]

Oh, the tranny's taken care of... it's the next step (before the engine) and will be a stage 4 4L80E from FLT.

You're right... but say I spend 11k on a LS7 instead of 9,600 on a 6.7L and make right at 700 hp but end up wanting more. Putting the SC on a LS7 would require the same amount of work and possibly more expensive parts.

It's a proccess. I'm gonna be happy with an N/A 6.7L I think... but if I'm not, there's always the next step.

11K for a LS7? Your talking complete right? (tranny, fuel pump,etc.) 700hp is not going to be street able nor efficient, N/A w/6.7L. Plan on rebuilding that motor every year. There's no replacement for displacement. More cubes will = more hp, less stress on internals, and more HP/TQ. I would have a 402 in mine already but I saw the light and proof.

[SS Killer]

11K for a LS7? Your talking complete right? (tranny, fuel pump,etc.) 700hp is not going to be street able nor efficient, N/A w/6.7L. Plan on rebuilding that motor every year. There's no replacement for displacement. More cubes will = more hp, less stress on internals, and more HP/TQ. I would have a 402 in mine already but I saw the light and proof.

I'll get 600Hp out of the 6.7L and be happy for a bit... then when I get restless and want something to do, I'll put a supercharger on it.

[SoHo48]

I knew someone would come back with that one! I think it would actually have to be a 15.4:1CR

haha picky ass arent you! but yea im in complete agreement. 15.4:1 and a steady diet of 106, maybe a pill or too and you should get 700 out of a 6.7