Moved this from Engine forum.

Well, I've decided that I want to ditch the GM aluminum EGR manifold with Qjet bolt pattern for something with a Holley (600 cfm 4160 vac sec) bolt pattern.

here's the engine spec's (which arent very exact)
(fresh rebuild)350 bored 30 over.Cast flat top pistons for about 8.5-8.8 CR.882 76cc heads. stock rebuild.206/212@.050 .425/440 112 LSA.Full length 1 5/8 headers through 2.5 inch pipes to flowmasters and full 2.5in tailpipes.stock HEI with 8.8mm wires.and the rest of the drivetrain is a stock TH350 and peg leg 2.73 rear. and 28inch tall tires.
The only things that are subject to change in the near future are a gear swap to 3.08 or 3.36 posi(within 1yr) and a head gasket swap to bump the CR up a tiny bit(within 1yr). and maybe a switch to 26.5 inch tall tires (2yrs from now maybe).

Engine may never see 5k RPM. Lets assume it'll almost always stay below 4500 while living the majority of it's life between 2000 and 3000RPM.

The popular dual planes seem to be the Performer, Performer RPM, Stealth, Action Plus, and Holley 300-36. But I'm open to other suggestions including GM manifolds that i might find at the swap meet. oh yeah, i'll be looking for the manifold in used condition at the car swapmeets.

oh, and is there anyway to install the heat shield/ oil splash thingy that's on the bottom of my GM intake onto an aftermarket intake? Would a good machine shop be able to do this. oh and while i'm at it, what does the splash shield do and is it good to have on a daily driver?

edelbrock perfomer

okay, edelbrock matches a cam much like mine to the performer and performer EPS. The performer says it has provisions for alternator and HEI, the EPS makes no mention of this, is there really a difference in the manifolds in respect to accessories? does anybody know?

Now I've narrowed it to Perfomer, Perf EPS and Stealth.

Performer... call them if you have questions.

The alternator provision is for a short water pump or the 3rd mount hole on a long pump bracket. On my vortec RPM intake, they have the hole for a long pump third mount. Must be for a stock 96' up serpetine bracket cause I haven't found a alt bracket that will fit. Some intakes have the boss undrilled, some don't have anything. Easy to see in a picture. Little tab sticking up by 1st intake bolt on LH side. Or RH side by the thermostat housing for a long pump. The only possible HEI related thing I can think of is maybe a tapped port for a vac fitting.
Might be in the way. Doubt it though. Normally if there is a problem with that port, it's that it requires a special fitting for a holley rear bowl to clear. Very nice of EB on that one.

For your app, a QJ might be better. Mileage wise.
And the stock 69 or so QJ manifold is usually better below 2500 rpm. But then again most people can't one hand an iron intake on and off.

Milodon makes a splash shield for SBC's. About $20 from Summit.

Yeah, well I'm stuck with the Holley either way i go. i know what you mean about the rear bowl, I have the fitting to make it work. I'll just try to find a Performer that has all the same acc. holes that my 87-up Performer has.

Thanks guys. I'll be looking for a Performer next week at Pomona. Then I'll take a die grinder to the Edelbrock markings and paint it orange. :D

I'll offer a differing opinion.

I replace a cast iron Q-jet intake w/ a perf. RPM on a similar motor. I also added 1.6 rockers at the same time. The car seemed to pick up power across the whole RPM range. It did not lose any bottom end... in fact, it may have gained.

In my opinion, the performer is only a minor improvement over a stock intake. If you are gonna spend the bucks, get a RPM, or an EPS. The performer is a 20+ year old design, the modern manifolds seem to work better.

I'll offer a differing opinion.

I replace a cast iron Q-jet intake w/ a perf. RPM on a similar motor. I also added 1.6 rockers at the same time. The car seemed to pick up power across the whole RPM range. It did not lose any bottom end... in fact, it may have gained.

In my opinion, the performer is only a minor improvement over a stock intake. If you are gonna spend the bucks, get a RPM, or an EPS. The performer is a 20+ year old design, the modern manifolds seem to work better.

Originally posted by Slowpoke70:
oh, and is there anyway to install the heat shield/ oil splash thingy that's on the bottom of my GM intake onto an aftermarket intake? Would a good machine shop be able to do this. oh and while i'm at it, what does the splash shield do and is it good to have on a daily driver? The best way to do this is to use this product if you don't have a roller cam:

Moroso 25050 Lifter Valley Oil Baffle, Small Block Chevy, including 18° heads

This not only blocks oil, but if you bend a pushrod it keeps hte lifters in their bores so you don't loose all your oil pressure.


http://www.moroso.com/catalog/images/25050_part.jpg

Imho, below 35 to maybe 4000 rpm, a stock Q-Jet and intake is hard to beat!!!!

And I gotta feeling that the early cast-iron intakes are of higher quality casting-wise then the newer aluminum stock Q-Jet intakes, again, jmho..

pdq67

Yeah PDQ, but i wanna get rid of the carb spacer and i cant bolt the holley to the stock Qjet manifold. nor can i afford to buy a Qjet and have it rebuilt with quality parts.

I'm thinking about the EPS now, my friend has an RPM with similar engine but a a little bigger cam (264 adv duration generic grind, step above RV supposedly) but i think his gears a lower (higher number) than mine as his engine revs up much faster than mine.

Sorry, didn't realize you had the Holley carb.

I don't know of any non-spreadbore intakes that are suited for your intended operating range b/c all of them except for the ESP is for higher rpm usage.

Go for it if that's what you want.

I don't think you want a Stealth b/c it falls into the Chevy Z-28, E-brock RPM and Holley 300-36 hi-po intake category, imho..

pdq67

Look at the GM ZZ4 intake. You can find them dirt cheap everywhere; it has both bolt patterns; and it substantially outflows a Performer or the like.

hmmm ZZ4 looks good. maybe i'll find a used one. so far it looks the best. thanks for the suggestion RB69!

RB... is the ZZ4 intake really better than the performer? Visually, it looks like a performer knock-off. Guess I learned something today.

I still say there is no need to fear using an RPM intake on this engine. My 8:1, small cam 350 seemed to work very well with the RPM manifold... better than I expected.