Anyone running these heads?
Do you know if the respond well to porting?
Do they have issues with stock flow numbers?
I'm considering a port job curious if anyone has already done it to these.
They respond well to some short turn work and some bowl work, and a few other changes..
I have the stock flow numbers at the shop, the only thing I do not like is they have a 1.78" installed height, I'd prefer a little more on some of the more aggressive cams. A switch in the retainers and or locks can get you more height.
I've worked on a few sets, and I am just finishing up a older set (ped mount, 1.94" int x 1.60" exh)
i realize there are better heads out there but 500 bucks as apossed to 1700 bucks is my issue. have a 2 year old and a 3 month old. my heads are the 1.94 intake 1.6 exhaust. bought them maybe 5 years ago. i think the part number was something like 300-551 maybe.
There actualy not bad looking heads,from what I see on Holley.I think a little porting and they would probable beat average TFS Track Heat flow numbers,even with the smaller 1.90" valves.
i got roped into buying these heads and i don't really have the cash to buy other heads that would flow better. afr 205 are on my wish list but that maybe a while till i get them. right now i want to continue to stay ahead of my brother in laws 68 dart running a 440 4spd. he ran a 12.95 1/4 mile time at the track i ran a 13.05 N/A. so really he is a little ahead of me but with nos i had him. my car was bogging bad when i wasn't running the nos.
I assume you mean on a 4.03" bore? They larger valve really helps on those heads, the new version they went to already had it done.
To make them good for youe combo it would cost over $500, for a few hundred more you could go with a Vic Jr that would yeild better results, but the AFR would yeild the best results and is really what I woudl recommend on your combo.
Why not sell the Holleys and upgrade when you can?
I went 11.8 @ 116mph 340RWHP on a NA 302 8.8:1 comp with the Holley heads and Intake, AFM cam etc, on a 175 shot I went 11.0 @ 131 and the car made 540RWHP/742RWTQ No traction
nice times i am assuming you have suspension mods to help pull off those times. grrr maybe i will hold off on putting cash into the heads and just have the car tunned on the dyno instead. that way i can put those holley heads on my pickup when i get some afr heads for my car. according to my mph when im on juice the calculators say i am making 428 rwhp with a 410 rwhp average.
i wish i could just port them myself and it wouldn't really cost me anything. btw the exhaust valves were upgraded to some nitrous valve. the shop that did it also cut down the valve stem . you can see how they tappered the valve stem through the exhaust port. they claim 5 cfm more flow on the exhaust that way.