What types of modifications do you sugest to get better gass millage more horse power.

 

Hard to do both, when you get more horse power you loose gas
mileage, The only thing I know that will work for both is to have
the heads cut ( shaved) for more compression, that will give more
power and fuel mileage. cut the heads about 65-70 thousants.
dont go over 9.1 to 1 compression ratio. that would be about
140 lbs . a factory new engine with a few miles would have about
120 to125 lbs