My 340 getting 6 mpg

Whata up guys !

A little update on the 64whiteghost aka my 1964 plymouth valiant.

Got my 340 running and broken in i havs about 150 miles left to hit the 500 miles. But i have one problem. Im getting 6 mpg

Im running an FST double pumper 750 with 67 jets. Idk what power valve yet. But im assuming it has the stock 6.5.

Motor: 340 .30 over

Cam specs: See photo. It is a custom cam and peak power is at 680p rpm

Cylinder heads: flow bench showed 235cfm

Rear: 8 3/4 3:73s with a posi

Im wondering if my 750 is too much. Power is crazy good and im happy with that. But my mpg is insane lol And im wondering if i need to go down to a 650 and if that would help.

Thoughts?



In wondering

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My timing is 10 initial and 34 advanced. I ordered a 4.5 power valve and im going to see what mpg i can get this saturday
Wooo, 750cfm is way to much carb. 600cfm is plenty. Then play with your jets till you get 18 to 20 vacuum inches at idle. What is your vacuum at idle now?