Holley 4175 power valve?

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DART66GT

DART66GT

62 Lancer GT - B Body 8 3/4
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I am rebuilding a list 7855, 4175 Holley. It is going on a stock 75 318 with performer intake stock dual exhaust ,recurved distributor. The car is a 66 Dart GT, 3.55 suregrip, 4spd O/D. Car weighs less than 3000. The carb originally comes with 562 jets and a 2 stage power valve. I did some research and found a few articles recommending going to single stage PV and moving jets up a couple of sizes. Especially in a light car with decent power. I do want to keep the best economy to power ratio I can. Thanks..........
 
well with a 318 i guess your not going to crazy with a camshaft, sooo i guess a 6.5Hg PV would be a good start. my question is...whats a 562 jet?
 
Holley made some mid size jets its a 56 1/2 (basically). Do you agree with getting rid of the 2 stage PV.
 
Wouldn't the 65's be a big jump especially since the carb's a spreadbore?
 
nope, its just compensating for the two stage PV. thats why the jetting in those things where lean..also another reason they ran like crap most of the time.
 
So this setup would be a good compromise between power and economy?
 
alot better then the stock setup. honestly tho, any holley spreadbore carbs are more or less junk for a performance app. IMO i would go with a carter thermoquad, one of the best carbs ever made.
 
Holley recommends single stage PV's for performance. I'd start with a 6.5 and go up 2 numbers on the jets.

Other 4175 oddities include the somewhat oddball float bowls which have no external float adjustment, and require the anti-pullover squirter nozzles. No big deals, but things to keep in mind.

If performance is the main goal, run a 3310 square bore and be done with it.
 
I am going to use the 6.5 PV I have from another kit. I agree with you C130 on the 2 jet sizes just gotta find 58's or 59's some. Went through my jets and found 2- 57's, 1- 60 and 2- 64's everything else is bigger.
 
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