990s?

[davec43]

Is it possible to make 990s a decent set of heads... Currently building a 489 and still choosing parts but trying to keep it as budget as possible

[SStrokerAce]

To paraphase a head porter I use:

Does anyone have any experience with these heads? The numbers on them are not very impressive in stock form. Do they respond well to port work? What kind of numbers can be had out of them? Also does anyone even waste time with them with all the aftermarkets out there? I am most interested in the exhaust. Again thanks for any help!

the #990s work OK on 468 to 540 cid range
usually use Edelbrock 454-R with 468 to 510 cid
and Super Victor for 510 to 540+ cid

i convert guides to 11/32 and run +.100 Longer 2.300/1.880 valves
and use Cams with near .800" Lift and higher most times

these Heads respond well to Porting + Valve Jobs

the exhaust ports can be made to flow pretty good, and more than adequate for the Intake sides, but they need careful porting as water is close in areas, and the actual exh exit dimensions are not much larger than OEM, just internally very different than OEM.

but the disadvantage is the tendency to crack on exh short turns over time , and the weight over alum heads, and the repair ability -vs- alum heads

it also takes careful port/short turn shaping to get the Bad Int Ports to get closer in Flow Numbers to the Good-direction Intake Ports.
there is more "flow number spread" between those 2 Ports than in modern aftermarket Heads.

Larry Meaux
Meaux Racing Heads

[davec43]

Thanks for your reply.... Trying to acquire some 781s or 049s.... Or I'm just going to save up and buy aluminum

[lftnwhls]

My 454 made 563Hp and 590ft lbs with a mild hydraulic roller cam 12.5-1 and a 950 Hp carb and 990 heads with no porting.