i just brought home my 03 gmc 1500hd 2wd today and absolutely love the power it has. I am taking it to the track tomorrow to see what it will do in the 1/8 mile so i can get some baseline numbers and see what it will do with every mod i do. As of right now i have changed the fuel filter, spark plugs and cleaned the throttle body a bit. My friend has been telling me if i get the truck to get a cam and stall converter but im new to these engines. The truck kinda feels slugish at the bottom end (has 3.73s with g80 locker) and i am thinking about doing the cam now and maybe a stall later. i want to reuse the valve springs, pushrods and lifters. i dont want to go to crazy just something with a little extra power for the bottom end but wont sacrifice the top end. i have been looking at the forums all day and found some info but not enough to select the right cam. also is it possible to get better mpg's with a cam?
Thanks, Abel

 

the comp 212/218 is a good torque cam. But with any aftermarket cam you will want to upgrade the springs and pushrods. And a 2600 stall torque converter would work nicely, but will be hard on the stock transmission. At a minimum I would do a the vette servo, shift kit and a tranny cooler such as the trucool 40k. The hardest part about adding power is keeping your foot out of the gas. some 4.10 or 4.56 gears will also help get that beast moving but will cost you a few mpg.

 

If he has an 1500hd then he has a 80e trans.

 

Is that good or bad?

 

its great. The 80e is a lot stronger than the 60e.

 

Gears, gears and gears. 3.73's should have never been put in these trucks.... it's a terrible ratio with the 80E in a heavy truck. Unfortunately the ratio I would like is 4.30... which is not available for the 9.5" 14 bolt as 4.56 is getting pretty steep for highway driving and 30.5" tall tires. I would tach close to 3 grand at 75 mph.... no thanks.

That said although normally discounted, on these trucks the change from 3.73 to 4.10 is fairly noticeable. Enough so I would never buy another 3.73 equipped one again.... Not to mention how the 3.73's neuter the tow rating to utterly pathetic numbers.

MPG is subject to driving style, tires, and weight.

212/218 would be pretty torquey.. That said I wouldn't really look for anything less than a 2800 rpm convertor. I have said this before as my stock 80E flashes to right around 2500 rpm..... Now the stall torque ratio in an aftermarket convertor will be better but still, 2800 minimum imo.

If it's not tuned, tune the thing first off. That makes the LQ4 a whole different animal all on it's own.

 

I have a 4.56 on 255/70's and it runs about 75 at 2600 RPM. Get the stall first, it amazes me how people always get this backward. I guess if you do the cam first, you will hate your truck so much afterward that it will really motivate you to get the stall in quicker. Get a Circle D in about a 3000 rpm stall speed. http://www.circledspecialties.com/p-...converter.aspx

You can thank me later...

 

Odd.... assuming you have an 80E in that truck with 30" tall tires.... 4.56 should right at 2900 rpm..... I tach 2300 with 245/75R16's that measure a true 30.5" at 75 mph. My speedo is bang on as I have a GPS based speedo in the truck at all times. That's convertor locked, in overdrive, which coincides with any online rpm calculator.

 

Nope, I have a 60e. That must be the difference I didn't realize the 80 had a slightly different OD ratio. I have an 80e sitting waiting on my FLT to go down. But for now its still strong...

 

80E is .75 and 60E is .7. Doesn't sound like a lot but at that speed accounts for around 250 rpm difference.