pskel350

I have 487 casting heads on my engine right now, but i have different ones to put on this winter.

I found this infomation on mortec.com "used on 71-72 350 LT1, 75cc chamber"

are these heads any good at all with the right pistons? I was thinking next winter when i build my new engine i could port and polish them and get the right pistions to get the CR i want. Is this a good idea, or are these heads no good at all?

89WS-6

Those arent bad heads, especially ported and polished. Why were you thinking so, because they were 76cc? Thats not too bad, I mean if you get high compression pistons it will still work good, and if you get low, well then you should get some torque, and then you can put a 400 shot and nitrous on it. HAHA!

RB83L69

Those did flow OK, but were intended to be used with domed pistons. Nowadays they're not real popular because that combo has a strong tendency to ping. Those motors were way off the pace of the 70½ LT-1.

With flat-tops they're good for about low-mid 9s CR, depending on the rest of the engine. Not too bad for a street engine with a real mild cam. But you'll get beat by people with better heads.

Sell them on e-bay or something, you should be able to get near enough $$$ to get something better. Or, put them on a flat-top 400; the CR will be between 10 and 10¼, which is about where you want to be.

jms

iTrader: (1)

It would be safe to say 487 heads came on hundreds of thousands (or perhaps millions) of 1971-1973 or '74 (four barrel carb) 350 equipped Impalas, Caprices, Chevelles, Camaros, etc.

The heads would have 2.02 intake and 1.60 exhaust valves if they came stock on a 1971-'72 LT-1 originally. I believe they should also have screw-in studs.

They are not bad heads (for originally coming on smog era 350s) but are very outdated now.

There are also 487x versions. Supposedly a little larger intake runner. Not sure of that. I've had both sets but never cc'd them.

Again, not terrible heads. Run 'em if you have to but there are several better heads out there.

jms

84TAProject

Ive got 487's on my t/a, and I beleive that they are 9:1 with flattops and 8.5:1 with dished. Of course guess what kind of pistons Im blessed with? These heads look 10X better than my 624 castings. My car runs fine with these heads, and though Id like to upgrade, I may find an older car and build a big block for it, not deal with emissions and keep the firebird as a good driver until funds demand new heads. They came on 350/270 and 350/330 horse motors, the former had 8.5:1 comp and 1.94/1.50 valves, the latter 9:1 and 2.02/1.60. This was in 1971 mind you, and they changed to net readings after this.