I'll be picking-up my 4.25" stroked .060" over 454 (496") on Saturday, and hope to drop it next weekend. I have a Performer oval, a Performer RPM Q-Jet oval, and a GM SQ Port #163. I can run either a 3310 Holley 750 vacuum, or a Q-Jet;I don't really have a preference one way or the other for the carbs. Due to hood clearance concerns, I'm probably gonna rule-out the RPM Q-Jet, which leaves the oval port Performer or the GM 163 intake.

Engine specs: 10:1
Heads: #781, w/2.19 and 1.88 valves, with bolw blending
Cam: Engle Solid HL-25 .560I/E, 242* @ .050", 286*Adv, on a 110LC
1 3/4" headers,
TH350, w/ a 11", 2400 stall Holeshot converter
12 bolt, which currently has 3.07 or 3.31 gears (need to confirm)

Edit: The overbore is .060", not.040". The Q-Jet is an Edelbrock 850 w/ electric choke I picked-up off a guy in the local trader paper.

Would I be sacrificing a lot of torque with the SQ intake? Would the SQ intake provide any top end over the Performer? TIA

Any body... on a BBC with oval heads, would a oval port Performer or a GM SQ port #163 make more mid and top end power? TIA Wes

The performer's rpm range is idle to 5000, youre cam should pull to 5500+. The RPM intake would probably give U more on the top end 5000+ but depends on CFM of Qjet U have. U should run a minimum of 750CFM a 800-850cfm would be more ideal. So it depends on your carb situation if the spreadbore carb U have is smaller than 750 run the 780cfm with the performer if spreadbore is 750 or bigger run the RPM intake. The performer should give U better low end but U should have more than enough with the 4.25 crank.

Wes,I would try the 163 intake..

Before I put a blower on my motor, I used the performer and it was fine, no complaints, of course I like Edelbrock products.

Thanks for the replies. My biggest concern with the Performer would be the engine nosing over around 4800-5000 RPM because of the larger displacement. The guys at Engle felt confident that the engine would pull hard to 5800-6000 RPM if I could get sufficient air and fuel to it.

I'll hold on to the RPM Q-Jet in case I go to a cowl hood or I can figure out a way to get a large enough air filter under the hood. I recall Chris speaking favorably of the Performer and posting some good times with his combo. So, I think I'll go ahead and give the 163 a try. I kinda think the factory intakes look better too. Thanks again, Wes

what year is the car that an rpm intake won't fit under the hood? i had a strip dominator with a 1/2" spacer under the flat hood on my 71.

Wes, for sure i would choose the 163 out of all your choices.

Thomas

Thanks again for the replies guys. I'm gonna give the 163 intake a shot and hope to fire it up within the next two weeks. As soon as it's running, I'll post the results. m71, I have a 1965 Malibu. Wes