Are there any performance gains of the RPM heads over the Performer heads? I think there is with the intakes, but the heads flow the same... one just has the crossover passages.

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

I believe the RPM heads are a lot better. The performer heads with the power package give the engine horsepower in the low 300's, and you can keep the engine emiisions legal with performer components. The performer RPM package ont he same 350 put out 420 horses, but was not emmisions legal. That extra power comes mostly from the cam and heads.

 

I'm not too sure about that. The performers are emissions legal and have exhaust crossover passages cast in. You could get these in the centerbolt style and 60cc to bump up your compression, you just need new valve covers. The performer rpm surely are more perf type with no egr and a 64cc chamber, but without milling, why use 64cc in aluminum on a 350?

My bet (I may be wrong, wouln't be the 1st time ) is that outta the box, slap them on the Performers in 60cc will slightly edge the RPM's due to the higher CR with advantages of keeping egr with sure, drops a few ponies from the extra heat, but makes for a friendlier street car.

 

The Performer and RPM heads are EXACTLY the same heads/castings guys (ie 64cc Performers are 64cc RPMS and 70cc Performers are 70cc RPMS), just with (Performer) or without (RPM) the exhaust crossover passages.

[This message has been edited by FastBroker (edited July 06, 2001).]

 

That is what I thought Fast... BTW, I have the 64cc Performer heads. Would running a non-EGR intake or simply using a block-off plate for the EGR be OK with Performer heads?

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

Just run a non-egr intake. EGR intakes are generally lesser performers anyhow, as they already got by the smog police so they cannot flow all that much...

 

My main problem is that I need to pass the sniffer every year. So I have a PErformer manifold on, but the EGR valve is not hooked up. I hate this county! I'm tempted to run a Performer/q-jet during that one day, and swapping to the Holley/Weiland or something the other 364 days, but I really don't want to mess with getting the q-jet running well just for one day. I wish I could just glue the EGR onto the side of the intake and hope the morons buy that... lol

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

I basically swap entire motors to get done what needs to get done.

Do what you gotta do....

 

This may not mean anything but in the Summit ad they are talking about the Performer and the Performer RPM heads. It said for more midrange and upper rpm power use the Performer RPM heads. I have no idea if there is a difference I am just repeating what the ad said.

 

I'm telling you guys that they are EXACTLY the same heads but either with or without exhaust crossovers...


EDIT: go to their website or look at their catalog. Careful scrutiny of the charts that have the P/N's displayed will show you what I mean. They should still list the Performer AND the RPM head Part Numbers on the same lines, even... ie, same runners, chambers, etc... Just those with exhaust crossovers are EO'd for street use and are highlighted in Green or Red or something like that.


[This message has been edited by FastBroker (edited July 10, 2001).]