The .509 cam with a 3000 stall is pretty aggressive for street driving and begs for a 4.10 or deeper gear in my opinion. 3.55's will help if you have something really tall, but to me they are not an extended freeway gear. Even 3.23's can get on your nerves at 75 MPH for 5 hours. I agree the 3.55 is a great dual purpose gear but I'd tone the cam down a notch or two.
Read THIS ^^^^^ and keep readin it. 3.55s SUCK in a heavy B body unless you're grandma goin for groceries. And really, don't even come back with some kinda "mileage" whine. To which I will say "go buy a Prius."
First, you said 3.55 gears. I gotta vomit. Second, you said 3000 stall. Ok, lets cover that all by itself. With a 3.55 gearset, your converter will still be slipping at highway speed. That creates excess heat. Guess what an automatic transmission's worst enemy is? Say it with me. H E A T.
Third, you said 509 or similar. Actually, I would recommend the Comp Nostalgia purple plus 509 version. WAY more modern grind and it'll burn tires around the old 509. Anyway, as Meepomous said, a cam like that requires IMO at least a 4.10 gear to even begin to get the benefits. Maybe even a 4.30 in a heavy B body.
Ok, "60" is not the tire height. A little ejemakashun. Tire sizes are like this here. Lets say for kicks you gotta 235 60 15 tire. Here's how it breaks down. "235" means that the tire's section width (from outside sidewall to outside sidewall) is 235mm wide. Simple huh? Ok, what about "60"? That means the sidewall height (from inner circumference or bead to the tread) is 60% of the 235mm section width. Simple again, no? Of course lastly, we have the 15. That simply refers to the wheel diameter the tire is designed to fit on.
So, how do we get HEIGHT from all that thank you Jimmy Carter for the metric system horse hockey? Here's how. You take the section width (235 in our example) then multiply that times our aspect ratio (60 series in our example) so 235 x 60% = 141. Well hold on, we know the tire has to be taller than 141mm, right? See, that's only the height of the sidewall, plus the tread. So, we have to multiply that times 2. 141mm x 2 = 282mm. But damn. We're still not through. Cause we know the damn tire is taller than 282mm (11.11"). What did we do wrong? Hay, remember that 15" wheel in the middle? So, 11.11 + 15" = 26.11". NOW we got somewhere.
If you followed all that, that is how to figure tire sizes. It sucks. I never have understood why they just could not go to sizing them like racing slicks. Like 28 x 9 x 15. So simple. Oh wait....they used to but Jimmah had to frig it all up.
