C5-R BLOCK 427CI with LS6 topend

[lingenfelter69]

Hello all. I'am thinking of...
-building up my 243's
-re use my ls6 intake
-port my 78mm throttlebody
-1 7/8 LG's
-very aggresive custom cam
-stock TI's

Question is what is the horsepower limits on the ported 78mm throttle body?
How much power can I get out of this engine's throttle body or do I need to step up to a bigger one? I would like to not have to buy a new throttle body if I can get away with it.

Shooting for 600 Horsepower, 500 #/feet of torque.

[Firebirdjones]

Sounds like you are spending alot of dough on the entire build, (C5R blocks are pricey alone),,,,,then you say you don't want to buy a throttle body??

When you've gone as far as you're talking, a throttle body is chump change. I'd personally just do it all right the first time and be done with it. Get yourself and FAST setup and skip the LS6 intake for a build like this.

[lingenfelter69]

Ya i have been humming and hawing over that. maybe i will look into a lsxr 102 over the winter or a fast 90. Iam justing being a cheap a$$. All i have is the block right now so i am still in my planning phases. Maybe i would be better off selling my ls6 complete as it only has a litte over 30,000 miles on it

[Firebirdjones]

Ya i have been humming and hawing over that. maybe i will look into a lsxr 102 over the winter or a fast 90. Iam justing being a cheap a$$. All i have is the block right now so i am still in my planning phases. Maybe i would be better off selling my ls6 complete as it only has a litte over 30,000 miles on it

I'd jump on the LS6 complete if you were in the states. Not sure I want to deal with customs shipping from Canada,,,,but you shouldn't have any trouble selling that anyway.

I know what you mean about wanting to save a buck,,,,completely understand. I just wouldn't do it on the intake setup when you have a C5R as a building foundation. That's a pricey little engine package I'd put some worthy heads on that with a FAST setup and easily surpass your HP goals.

[ramrod]

My fav block! Good luck!

[lingenfelter69]

Going to get the block cleaned up here shortly. Is 4.150. Going with 4.155 X 4.125 for 447ci or 4.152 X 3.945 for 427ci decisions, decisions...