Thread: How to choose the correct Heads

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across the line is usually right around 62-6500

Originally posted by shawn74
across the line is usually right around 62-6500

I THINK YOUR HEADS ARE ALLRIGHT.I WOULD NOT GO OUT AND SPEND THE MONEY ON HEADS.I DON'T THINK IT WOULD REALLY MAKE THAT BIG A DIFFERENCE.THE PROBLEM I THINK IS YOUR STALL SPEED BEING TO LOW LIKE PAT HAD SAID.I WOULD PUT A LOOSER STALL IN 3,500 TO 4,000 AND I WOULD ALSO LOOK AT YOUR SUSPENSION.MAYBE YOU ARE NOT (HOOKING UP) AS WELL AS YOU THOUGHT.

yes and i think the cam is to small. if you have 12 to 1 it could take more. like erik said and i said to work on the suspension. the holley heads may not be the best. but i shure do not think it was all your promblems.and would of put you in the low 12s with not very much work

Well I wish I would have found you guys about a month ago because I sold the heads So I still need to buy a pair. What would you recomend?

Call AFR and talk with one of their tech people about your application so they can make a recommendation. I guarantee you will be pleased with these heads.

Originally posted by rumrumm
Hands down, AFR 195 heads, are the best flowing head out there for their size, and they should be a great flowing head for you. Go to their website and check out the 180's and the 195's.

www.airflowresearch.com

THE AFR'S ARE GOOD HEADS.THE PROBLEM IS THE FLOW DATA IS FROM 1998 AND SINCE THEN MUCH ADVANCEMENT HAS BEEN MADE.I WOULD NOT GET TO EXCITED ABOUT ANY GIVEN BRAND NAME.ON THE DYNO OR AT THE TRACK THERE REALLY WON'T BE A LARGE DIFFERENCE FROM HEAD TO HEAD AS LONG HAS THE PORT VOLUME IS ABOUT THE SAME.THE WHOLE IDEA IS TO HAVE A SMALLER PORT VOLUME WITH HIGHER FLOW NUMBERS.

I recommend AFR because I have personal experience with them and they have met my expectations in every way. I cannot recommend Brodix or other good flowing heads because I have no experience with them. A test done around a year ago by Chevy High Performance magazine compared all of the aluminum heads on the market, and AFR topped each category. But you are correct about the right head for the right application. Too big or too small is not good, especially when you are paying out $1200.00+ for a set. Hence the reference to calling the tech dept.

Originally posted by erik erikson
WHEN YOU CROSS THE FINISH LINE HOW MANY R.P.M.S. ARE YOU TURNING?

Great heads over good heads will get you a couple cars lengths which converts to maybe a tenth or so.

But, there's nothing that will get you down the 1320 more efficiently than proper gearing.

If you shift at 6500 rpm then you should be crossing the finish line at 6500...that's the key to the right gear.

I agree, it seems you should be getting at least to the low 12's

BTW, aluminum heads save you weight which is a good thing but they have to be extremely hot to make the same HP as an iron head making everything else equal.

Aluminum absorbs combustion heat and you don't get the expansion of the gases like you do with an iron head. With aluminum just make sure that the head is already very hot before your run.

Besides the things above, the key to putting together a real runner is to have all components matched to run at the same RPM range.
Starting with cubic inches and bore vs stroke ratio (is this an rpm'r or a torque'r). Then match all these things: Carburation, intake manifold, head port and valve size, compression, cam, headers, tranny and rear end gears to that rpm range.

Where many guys get in trouble is they tend to copy what other guys are running that have different applications instead of figuring out for themselves what will work best for their own application.

This is the difference between the pack and the guy that takes home the trophy every week.

Shawn, just keep at it and you'll get there.

ha shawn heres a good idea i use them and when there ported and polished they flow better then the bowtie heads

The '96 and later smallblock "Vortec" 350 cast iron heads are a very hot item. These "L31" heads with casting number 10239906 and 12558062 or PN-12529093 (bare), flow great numbers for a production head, even better than the Phase 2 Bowtie cast iron head, when fitted with 2.02/1.60" valves and bowl ported. The complete heads (PN-12558060) come with 1.94"/1.5" valves and pressed in rocker studs, but can easily be fitted with 2.02"/1.6" valves and screw in studs. Chamber volumes are 64cc and intake port volumes are 170cc. The Vortec heads have raised intake ports and "fast burn" chambers. The heads require the use of narrow body "self-aligning" rocker arms and center bolt valve covers. They will bolt to any Gen.1 block.
The price per pair for new complete Vortec "L31" 350 SBC heads (PN-12558060) is about $485.00