SBC Performer or Performer RPM?

[Riley]

Which would be better for marine use? I'm rebuilding my SBC, installing Vortec heads, and I'd like to keep the Quadrajet carb. Unfortunately, the only manifold that is available for this combo is the standard Performer. I plan on limiting rpm to 5200-5300, will this be enough manifold? HOw does this manifold compare to the stock cast- iron GM high-rise for the Quadrajet?

Also, I see GM offers an aluminum intake for the vortec heads that can be used with a spread-bore carb. Does anybody have any info on this intake, in relation to what Edelbrock has to offer?

Any info would be appreciated!

[MOP]

Jamie has a good handle on e manifolds that will work well. I am sure he will chime in. I also love the Qjet "infinitely tunable" and they very rarely leak, if I had one I would run it. I have a new Holley so will run that for now.

[GKricheldorf]

Can you get an adapter for the manifold that changes it to spreadbore for the q-jet? I know edelbrock makes them.

[Rootsy]

Adapters KILL performance due to transitions and undercuts, etc... avoid em if you can...

riley,

how much camshaft are you planning to run? how much compression? you already answered the cylinder head question... exhaust??? this will dictate what you want for a manifold... honestly.. the RPM is a bit much for BONE STOCK vortec heads and any camshaft under 230ish duration @ .050... the performer EPS is a better choice or the high rise dual plane GM manifold.. trouble with the EPS is that it is a square bore for a holley, etc...

yes i do run an rpm airgap... i have enough of everything short of camshaft, to make it work alright...

JR - measure twice.. drill once :yes:

[jc]

Which would be better for marine use? I'm rebuilding my SBC, installing Vortec heads, and I'd like to keep the Quadrajet carb. Unfortunately, the only manifold that is available for this combo is the standard Performer. I plan on limiting rpm to 5200-5300, will this be enough manifold? HOw does this manifold compare to the stock cast- iron GM high-rise for the Quadrajet?

Also, I see GM offers an aluminum intake for the vortec heads that can be used with a spread-bore carb. Does anybody have any info on this intake, in relation to what Edelbrock has to offer?

Any info would be appreciated!

I used Edelbrock Performer RPM Vortecs (part#EDL-7116) on my Vortec heads. I used carb adapters to re-use my Rochester carbs from Mr. Gasket. Several companies make these carb adapters. The carb adapters were 15 bucks ea.

I used The Performer RPM's over the stock Gm's for Edelbrocks claim in horsepower gains and its 1500 to 6500 RPM range to go with 9.1 to 1 compression and a 212/222 @50 .435/.460 lift cam. The Performer Vortec (part#EDL-2116) operate in the 1500 to 5500 RPM range and excepts both squarebore and spreadbore carbs. You might want this manifold if you are running less cam/comp. Both are listed for Marine use. http://www.edelbrock.com/automotive/index.html

Marine use.....I've used Aluminum Intakes and Heads for years in Saltwater without a problem, of course I flush, not only my engines but wash my outdrives and hull down with Salt Terminator and fresh water immediately after I trailer the boat. I personally would do this regardless of Marine only or Auto engines but I know boat owners that don't.

As for better.....I think that boils down to just how well you plan to take care of the boat.

[Riley]

Thanks for all of the info. Jamie, I should have emailed you direct, you seem to be the resident sbc guru here!

My whole intent on this re-build is to take my 1990 350 Mag from 270 hp to around 340-350 h.p., and not break the bank in the process. From everything I've read and heard, the Vortecs seem to be the most cost-effective modification to "head" (pardon the pun) where I want to go. Right now SDPC is selling a complete upgrade kit for installing Vortec Heads, including the heads with better valve springs, Performer Intake, and all fasteners and gaskets for under $900. I planned on adding a SCAT 9000 crank, PM rods, and hypereutectic pistons. Pending results found here on this board, I'm leaning towards the GLM aluminum exhaust manifolds. Cam selection yet to be made, but I like what I've read about the Comp Cams 262 X-treme Energy.

Or, I could just pull this engine and install a GMPP 350 Vortec-330 h.p. crate engine. I've tried to set my re-build budget for $2000, but for a few hundred more I can have a brand new engine......and a complete 350 Mag, too. Hmmmm....

If anybody has any other suggestions or combinations that they've had some luck with, I'd like to hear them.

[Rootsy]

Chris,

if you plan on swapping cranks and rods why don't you just push her out to a 383 for about the same money?

nuthin wrong with the vortecs... but i WOULD opt for the *high lift* versions for the little bit extra...with stock vortecs if you ever plan to run anything with more than .480 lift you;ll have to machine then...

figure out what you want to run for compression, cylinder heads and exhaust then we'll talk camshaft.. 350 pshp with a 383 running on 87 octane isn't very difficult to do at all.. and for the price of a 350 pretty much... think about it...

i am far from a guru.. i think the likes of buizilla and big griz and such qualify as that... i just knwo enough to be dangerous ;)

JR

[Riley]

Jamie, I've give A LOT of thought to pushing her out to 383. Problem is, I'm terrified that the extra 33" might be the final nail in the coffin on the Alpha One. I'm take it easy getting on plane and I don't do any wave hopping, but I have been known to slam 'er open from 3 grand to WOT. I don't want to get in a situation where the engine is chewing up outdrives on a monthly basis.

[Rootsy]

Chris,

it isn't about the cubes.. it's about the torque... 350 or 383... if you are making 350 hp @ 5000 rpm, torque is teh same.. it is just EASIER to make it with the 383...

a 350 can destroy an alpha as easily as a 383 or a 454...

JR

[CDMA]

I am with root. Its not what you got, its how you use it.

Case in point....my driving style ate two alpha's with a stock 350.

Chris Von blow up alpha's with an inline 4....

[jc]

Or, I could just pull this engine and install a GMPP 350 Vortec-330 h.p. crate engine. I've tried to set my re-build budget for $2000, but for a few hundred more I can have a brand new engine......and a complete 350 Mag, too. Hmmmm....

I chose 2 of these Vortec 330's for my boat........2099.00 at Summit 100.00 ea for delivery.

Jasper wanted 2499.00 ea. for 260hp REMANS plus a 300.00 dollar core charge. I'll take brand new 330hp over REMAN 260hp any day.

Sorry I'm not a GURU. Just a boat owner.