I'm currently running the 302 clevland with the 2 barrel. I'm interested in going the 600/650 4bbl with stock 2v 351 manifold... is this the best option. When were talking about vacuum secondaries does this mean that they cause suction by vacuum, or compresion by vacuum (or have I got it all up the wall).
Would twin carbies be the go? Is it hard to source a manifold to suit, and what type of carbies work best using the twin system, what i mean is can more power be gained using the two smaller carbies or just going the larger single carbie? Is there much difference in the fuel consumption.
Would there be significant issues with tunning and the choke line.
What costs would be involved going either the twin or single carbie, and the best brand for money?
Has anyone ever done this before... Any info would help heaps.
I currently have the stock exhaust manifold (soon to be extractors) with twin 2' system, and the engine is supported by a c10 with 8' diff.
Vacuum seconday is vaccum from the inlet manifold.
the amount of petrol being injected is the amount being injected, twins look good, but are really only used as big carbies cost more, and sometimes people outgrow the amount a single carby can be jetted to for delievery of fuel.
Keep it simple single carb, rebuilt, jetted correctly, and tuned nicely is all you want, maybe a spacer plate for a bit of accelration down the carby works well though.
I did put something here, but it vanshied, I think
See if you can source a 4 barrel manifold, either an aftermarket one or one from an XC or later engine. The two barrel ones fitted to the 302 on the XA and XB dont allow much improvement even with a 500 holley or similar. You can usually pick up the XC manifolds at swap meets etc for $40.00 or so.
Vacuum seconaries are operated by vacuum, this means that the secondaries only open when the engine is producing enough vacuum. So most of the time you're only using the front 2 barrels, but as the revs increase, the secondaries open to add more fuel. Can turn them into mechanical secondaries with a well placed bolt, which makes for a wicked induction sound.
How do the mechanical secondary (with well place bolt) help when it comes to power. Do the 4 barrel really produce better power? Has anyone any idea on price to get a carbie recondition? Can it be done as well by me [Knowledge is limited though, but mechanically minded].
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