denscor

I'm getting ready to order my heads but I am having a hard time choosing heads.I like the Mast 305 LS7 heads but they flow 388 . I also have been looking at PRC LS7 285cc they flow 415. Help me choose!

MVP'S ZO6

Well I'm assuming that your already willing to fork over the money for the mast heads so the choice is simple.

Just curious what kind of power are you after? What are these heads going on?

denscor

Around 1000. They are going on an ERL Super deck 2 434.

BLOWNBLUEZ06

My recommendation: Don't get too caught up with flow #'s.

Flow benches are different. Even using the same bench, many people are guilty of only looking at the highest lift #'s. Sometimes even #'s that aren't achieved with the cam being used. Look at the #'s across the board. Regardless, the MAST heads are top notch and unparalleled in my book.

FixedRoof

With the money spent on ERL Superdeck, top it off with the MAST heads. They are some of the absolute best LSx heads available, might actually be the best... lol

MVP'S ZO6

AGreed with both.

As bret said, to hell with peak flow numbers. Hell, some manufacturers will give u flow numbers at 1.000. (just a marketing thing)

Also mast heads are probably the best out there so if u can afford em and u already have the engine combo u have then go for it.

jobberone

For the money the MAST heads are the best. What kind of boost numbers are you looking to use?

denscor

My current setup I have 15lb plus max out the gauge with the biggest pulley I can run.(4.730) I'm going back to a 4.00, so it should be around 20lb.

MVP'S ZO6

What is your static compression ratio going to be and what are your cam specs?

Also, how are you calculating your approximate boost level? Reason I'm asking is because if your guessing based on your old engine and the current pully size, your going to be off on your boost numbers because of the larger engine Ect.

jobberone

At 20 lbs you will be fine with the MAST heads 4 bolt pattern. Just use a good gasket and overtorque 4-5 lbs at most. You may see less boost pressure with the MAST heads but increased flow and HP.

robert miller

1stGlance

Mine went from 12.5 on a stock LS1 to around 6 -7 on a forged 402 !!

denscor

Lower boost would be better for me! Yes just estimating boost. Compression will be 9.6. Cam specs are Ragin Racin V2Blower cam 232/256 114 .660/.660.

jobberone

I think that cam is too big. That's a lot of lift and duration.

denscor

I will try it and see. That is with the LS7 rocker arms.That is the cam that the Ragin Racin z06 car has and it has made good power.

MVP'S ZO6

She's gonna idle like a pro stocker with that cam. Should pull like a freight train though. What lobe are you using? Is there any advance ground into the cam? If so, how much?

Another question (cylinder head choice pending of course) did any one calculate how much Vacuum your engine will have with that cam? Also, your probably not going to make 1,000 with that blower pully.

Brian Tooley C5

Of all the heads made for supercharged C5's, which ones run the fastest down the track? Just curious...

mdaniel

There are stock headed cars in the 8s. Spend your money where it maters.

denscor

No did not calculate vacuum. I should be close to my goals correct? It makes 850 now and does not run right. The motor in it now is a TSP built LS7. Our signals got crossed and it came back with 11.4 compression, so we used a .120. Now it has no quench ect.The runs like a lazy motor.This will fix my problem plus I will not be limited to how much boost to run without worrying about it popping! lol

jobberone

That cam is on the edge for hyd use although people do it. You may have some vacuum issues with that small a motor for that cam. You may consider speaking to some aftermarket lifter guys about using the LS7 lifters with it.

I think you can make the power you want with a much smaller cam, lessen the need for bigger springs, lighten the load on the valvetrain, not have vacuum issues, idle easier and have less driveability problems.