I bought these heads for my build. Good deal or what?

eBay Motors: 340292 S.B. Chevy angle plug heads, 2.02 1.60 (item 200017274798 end time Aug-20-06 19:00:00 PDT)

They look like pretty good heads for the price.

 

Good score man!!! I am jealous! I need a break like that to keep me going with my car.

 

The guy building my engine said that he had a pair of these heads back in the day on a z28 and they are killer! I've been doing some searching and I can't seem to find the intake size. All I can find are valve sizes and that they were a high performance over the counter replacement. My guy said that they were a little known upgrade available from the factory. Anyway, they have been worked over and ported already so they should do the trick for my 355 buildup.

 

They were among the best, back in their day. Long since surpassed; but still a good casting.

I would hardly describe them as "little known", though; they were at least as popular and familiar in their day, as Fastburns are now. They were the first factory casting with angled plugs. You could spot them from the stands at the circle-track races.

They never came on vehicles, they were strictly an over-the-counter "service" part. They were quite expensive at the time.

They're pretty much a typical double-hump casting except for the angled plugs; except they're a little more precisely cast than most. The push rod pinch can be widened out more than on typical stock heads because the hole is smaller and/or better located, and there's either more meat or the casting is moved back farther in the direction of porting, than in other factory heads, in several critical places. They DO have the accessory bolt holes, which is ABSOLUTELY CRITICAL; their brothers the 291 castings, don't have those, so you can't realistically install them on one of these cars.

Intake valve size is determined by machine work, not by casting; which is why you can't "find" it. It's not a property of the head itself, as such; doesn't become a characteristic of the head until it passes through a shop. IIRC though, they came rough-cut for 1.94 valves (although I could be wrong...), but nobody ran them that way. Everybody put 2.02"/1.6" valves in them, which was a big as would go in them without the valves touching. Very few people ever bought them and just stuck them on their car out of the box and ran them. They were quite expensive, and typically only the serious racers with $$$ to spend, would buy them; and they typically maxed them out. Very different from today where there's lots of CNC-cast "street" heads available.

Oh well, enough nostalgia. Back to the point...

They'll make good power, nothing like good modern aftermarket heads or even Vortecs; but better than about any other factory casting. So, not a bad deal, for that price, as long as they come mostly complete with GOOD parts (not just somebody's used wore-out junk just stuck on them to take good-looking pictures) and you don't have to spend alot of money on them to make them into reliable runners.

 

Good score ! They are a very good source for increased flow & HP gains across the RPM range...

...however, be prepared to spend $$ on headers to fit the angle plug heads.

A few years back, I picked up a set of GM Performance Bowtie Phase II heads for my '70 Z28 w/ 388 stroker engine(very similar to the heads that you just picked up) and had to use Hooker Super Competition headers to work w/ the angled spark plug. Most "standard" headers don't support the angled plug.

Just thought I'd throw this out there...

Good luck w/ the new go-fast parts !!

 

thanks for the info and nostalgia guys. I hope these heads do the trick. I need heads now because my engine goes in the car in two weeks. With my other parts, I'm expecting around 400 horsies out of it. If these heads don't work like I like, I'll probably just buy some aftermarket ally heads but thats later!