My truck is a 1971 Suburban with a LQ9/4L80E/NP246 drivetrain in it. The motor is stock other than shorty headers and a 210/218 .551/.551 114 LSA cam. It has 38x15.50r16 tires and 4.10 gears. I'm looking for a little more pep
off the line. What would you guys recomend? I'm debating between a higher stall, or lower gears such as 4.56 or 4.88's. Which would hurt my gas mileage more? I only get about 10 in town and 13 at about 75-80mph, so I don't want to sacrifice much there. Thanks.

 

gears will make it worse, a stall might not depending on the str. size
I would go with the converter.

 

well do you do more highway or city?

gears = city imo

 

Gears for sure..

 

I'd say about 60% city driving. I think I'll try the converter for now. I want to swap over to a L92/L76 setup eventually anyway and a bigger cam, so it will be needed then for sure.

 

You will notice a gas mileage increase if you do gears man. Every truck I have ever owned I had 36 and 38 tires, I always ran 488 gears. Gets the truck thinking its turning closer to stock tires. With 38s ur gonna want a 488 or a 513. A converter is gonna hurt the mileage and heat the trans, you have enough motor you just need more gear, its working to hard.