Does any one know what heads these would be 202s or otherwise? They came with the car when I bought it I'm trying to put together some info on the car as to what exactly I have. Eddlebrock performer heads EOD21546. Any idea if these are good or not or what kind of horse power increase they provide? They are on a 350 (1991 z28) the 350 is not the original motor and I have no idea what it came out of (was a 305 car)

 

Can you rewrite that a little more clearly? Are you saying you have Edelbrock Performer heads on it? Im pretty sure those are fairly nice, though way overpriced. They're way better than the factory heads and most junk smogger heads that people call "202" heads just because they put 2.02 intake valves in them.

Ignore anyone who says they have "202" heads. It means absolutely nothing.

 

The number that starts out "EO" is their CARB EO (CA Air Resources Board, Executive Order) number; that's California's certification that they are emissions legal. It's not the part number. However, given that they have an EO #, that means they are the Performer, NOT RPM, series. Not hard to look em up on Edelbrock's web site.

They're absolutely NOT a "max power" type of head. That's not what they were designed for. They're a good solid street head. Pretty decent for what they are but not necessarily race winners. OTOH, given the questions you're asking, it doesn't sound like that really matters too much.

They aren't "202s". That's not their casting number. However, they may have 2.02" intake valves, for whatever that's worth.

Hard to say about "increase". That depends on 2 things: what some random motor (what you've basically got) started out at, and where it ended up. Right now all you know is where it ended up. Not enough info to talk about "increase" since you have no way of knowing about "increase" over what.

It doesn't really matter what the motor "came out of", as whatever it was, it almost certainly no longer is. Odds are VERY high it's been "rebuilt", which destroys all traces of "came out of" properties. Best not to even go down that line of inquiry because it leads NOWHERE. Instead, examine THE PARTS it's built out of, and THE WORK that was done to it; things like, what pistons did they use, what cam is in it, what machine work did they do, stuff like that. What the motor "came out of" is no longer relevant.

 

Alright I see what you mean there really isn't any way to tell what's been done to it without ripping it apart it seems. I really appreciate the responses though. It's the nature of buying a used car you never really know what you're getting. Car runs good and is pretty fast so that is all that really matters. Thanks again dudes and happy cruisen

 

Yeah that's a fair assessment of the situation... you can tell a few things from the outside, but the more detail you want, the more likely it is that you'll have to do a tear-down. (which is why they call it that in racing; you wanna see if the guy is cheating, you gotta tear it down)

If it works right and is satisfactory, then by all means, just accept the mysteries and enjoy it for what it is. The details won't really start to matter until such time as you want to make changes.