speedracer5532

iTrader: (8)

I just got a LSX block and am planning on building a 427. I would like peoples opinion on heads and intake for a supercharger setup. I have been running AFR 225 heads and a Tony Mamo ported 90 mm FAST with my F1A Procharger with great results. I have a street/strip car, well kind more of a street car. I will run a hydraulic cam and I don't plan on spinning the motor over 7K.

Which kind of heads would be best for my application: LS7 6 bolt heads (either All Pro or ET) or a good cathedral port head like AFR?

What about a Beck intake vs my ported FAST or a LS7 intake?

I basically want to know is it worth it to go LS7 stuff for my application or stay with AFR heads and what about a Beck Intake for forced induction? The LS7 stuff would definitely cost more and would have to run Jesel rocker arms which aren't cheap.

Jake@EPP

Hey John,

We have a 8.5:1 lsx going together here. Its a turbo motor but we are using a NICE set of allpro heads from WCCH. They should be here next week, they do not take 4 months to get which was nice.

For what its worth, the mamo fast and cylinder heads would sell pretty quick as a matched combo.

What is your overall power goal for this? Either way you go, its never enough

speedracer5532

iTrader: (8)

Hey Jake,

Yes agree no matter what we always want more power.

I turned to boost up to 18lbs with my 402 but never dynoed at the 18lbs but I figured I had to be around 1000 rwhp. I want to not run more than 15 lbs on the street with pump gas and still be around 1000 rwhp if possible.

bifster

what r you guys running for camshafts to be running that compression on pump gas.... the valve overlap must be huge... wow I was running numbers th eother day and even with a static 9:1 compression and 15psi I was in alcohol territory ..... I dont mean to hyjack but I just dont understand .
ps im not just a book junky either hahaha thanks

speedracer5532

iTrader: (8)

On my 402 I was running 9:1 CR with a 236/248 113+x cam. If I stay with a cathedral port head then I will most likely run the same cam but if I go LS7 heads then I would definitely change cams and I plan on staying around 9:1 CR.

Patrick G

iTrader: (14)

With forced induction, the exhaust is more critical than it is NA because the increased volume of gasses is still expelled by natural means (for the most part). That means you have to run a head with incredible flow on the exhaust for a balanced system. Think about it this way: If your goal is 1000 rwhp, you should have an exhaust port that can flow what you would expect a 1000 rwhp exhaust port to flow. An 85cc port with a 1.60" exhaust valve may not be enough.

In this regard, the AFR 225s are outstanding. The exhaust is better than almost any head on the market thanks to the clever wedge design of the chamber and generous flow. There's also quite a bit of room to run a larger exhaust valve compared to the LS7 style heads with their oversized intake valves.

I like the idea of running a sheet metal intake like a Beck for boost over 20 psi, but if you're wanting to keep it closer to 15psi, you may not gain a lot over the Mamo-ported FAST 90.

speedracer5532

iTrader: (8)

Thanks Patrick. I kinda thought the exhaust flow would be more critical than the intake flow in forced induction. I will continue to run AFR heads and just wait until Tony is done designing the AFR LS7 head, which is about a year away, to run a LS7 head.

02SSLE

iTrader: (26)

Patrick I got my new cam in and man it sounds sick.

DanZ28

iTrader: (5)

I was looking at the all pro's as well, very nice heads but at $5700 with rockers my budget would have shrunk considerably for the rest of the build, lol. I went AFR's for now as well for my LSX 427 build but will upgrade later to a 6 bolt head. I'm also going to use an LS2 mani, maybe change to a SM later on as well. Good luck with the build!

Dan

stevieturbo

If you cant run 15psi on 9.0:1 on pump fuel, then you need a new tuner.