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I'm currently running Edelbrock Performer intake on my 71 with L48 engine.
I'm thinking of going EFI way with sniper EFI.
I was looking at Edelbrock 7501 Performer RPM air-gap and Blueprint H8002K heads when doing this.
Was also looking at camshaft change but that is hard to choose as there are soo many. The closest I got was Howards 111145-12 but tech support suggested CL113215-10.
Otherwise the engine is stock.
Do I have to change the intake to run Sniper or is spreadbore intake OK?
Is anybody running upgraded engine with stock TH400, that includes converter, with EFI?
Spread bore/Square bore is no different to the EFI as long as your intake is dual drilled (which I believe yours is) for the Square bore bolt pattern. The real question you should be asking is “Dual Plane or Single Plane for the Holley Sniper?” There are known metering issues running a dual plane intake with that EFI system. Single plane intakes allow all runners to share all injectors, allowing the sniper to to operate more efficiently.
Choose your heads first and wisely. Cams come and go, but heads are usually there to stay. Be realistic about what you want out of the engine and understand the limitations of the stock internals.
I'm thinking,, if you already have the air gap intake, ok, use it,,, if your going to purchase a new intake, don't get the air gap,,,,, EFI will be happier with single plane style,,,,,just my $.02,,
Was running a 2101 and a spreadbore before switching to the Sniper EFI, but wanted a square bore manifold. Went with the EPS manifold then read articles about dual versus single plane with EFI, so the new manifold was modified. Been running excellent all summer. T
Performer RPM with Dart heads, ZZ9 Cam. Perfect combo, 450hp
Interesting. I checked, Performer RPM and RPM air-gap have the same intake manifold height.
I thought that air-gap is higher due to the design.
Both have same rpm range 1500 - 6500 rpm.
Interesting. I checked, Performer RPM and RPM air-gap have the same intake manifold height.
I thought that air-gap is higher due to the design.
Both have same rpm range 1500 - 6500 rpm.
Are you sure about that??* There were some very long C3 intake height and hood height threads and the consensus*was that the Performer RPM and Performer Air Gap (non RPM) would both clear the later C3 hoods, but the combination of RPM+Air Gap's increased height made hood clearance a real problem in a C3 stock hood.* -If there IS a height issue with RPM+AIR Gap get the Air Gap and just cut down the divider.* The colder air is what you want and cold start won't be an issue with EFI.
I like Terry's solution. Intake wave tuning is intake wave tuning; there's no getting around it; the longer runners with a dual plane intake is going to prop up the low and mid-RPM torque curve; why lose it? The air / fuel distribution issues of a dual plane are there with a carburetor*why is it so much of a bigger deal all of a sudden when it's a computer dumping the fuel into the venturi's rather than a dumb carb??!?
Are you sure about that??* There were some very long C3 intake height and hood height threads and the consensus*was that the Performer RPM and Performer Air Gap (non RPM) would both clear the later C3 hoods, but the combination of RPM+Air Gap's increased height made hood clearance a real problem in a C3 stock hood.* -If there IS a height issue with RPM+AIR Gap get the Air Gap and just cut down the divider.* The colder air is what you want and cold start won't be an issue with EFI.
I like Terry's solution. Intake wave tuning is intake wave tuning; there's no getting around it; the longer runners with a dual plane intake is going to prop up the low and mid-RPM torque curve; why lose it? The air / fuel distribution issues of a dual plane are there with a carburetor*why is it so much of a bigger deal all of a sudden when it's a computer dumping the fuel into the venturi's rather than a dumb carb??!?
Adam
Yes both are 4.720 in high! According to Summit and according to Edelbrock websites!
One of those Weiand manifolds might be a single plane and by all reports an excellent manifold. T
If this is the intake “shootout” series, I think they had separate articles for the dual planes and the single planes; the “Street Warrior” Weiands were on my short list back when I was going to run a dual plane and I was only looking at dual planes so I think they’re dual planes.
09-23-2018, 06:33 AM
engine upgrade help
