Wordguy

I'm installing a comp cams xr288hr cam with 236deg intake and wondered if I can port my L-98 heads and machine the heads for larger springs or should I just buy a used pair of aftermarket heads?

69 N.O.X. RATT

I would think that those heads would support 500 HP if ported. Almost any decent head can be ported to out perform almost any unported aftermarket head. I would find a shop in the area and ask them what they can do with those heads. You can check http://www.chevyhiperformance.com and they recently did flow tests on several stock and aftermarket heads. Air Flow research has a formula that gives you a very good idea how much HP your heads will support. I believe it is air flow in cfm multilpied by .2571 mulitplied by number of cylinders = HP (under ideal engine tune)

Example: At max valve lift your heads flow 290 cfm. Mulitply that by .2571 = 74.55. Take that number and multiply that by 8 = 596HP :chevy

89gta383

.2571*8=2.057

500 hp divided by 2.057 = 243 cfm's needed, roughly to hit 500 hp.

I've talked to shops about the L98's and they say they can get a max of about 250 cfm's out of them. The problem is, after port work and valve job, and such, you could have bought an off the shelf head like the Trick Flow 23* which flows better and costs about the same.

korvetkeith

If your Jonnyboy Lingenfelter!