I have not posted here for a while, but I thought you guys might find this interesting. This weekend I installed a set of AFR heads on the following vehicle - 1999, 2500 series, 4X4, 265/75R16 tires, EX cab with long bed. Engine mods - Hamm headers, free flow exhaust, Hypertech programmer, electric fans, UPD intake, and a 212/218 comp cam. With the above mods, 1/4 mile times were about 15.5 in 90 degree weather on a G-tech. After the AFR heads it dropped to 14.8 - 14.9 with a full tank of gas and similar weather. Not bad considering the engine has 100,000 miles, hypertech tune and stock 24.5 pound injectors. I wonder what bigger size injector I could run without having to worry about a custom tune? I would also like to say there were no issues with the heads. I read in the engine section about people saying threads were not threaded all the way or holes were not deep enough on their set of heads, not mine, even the intake bolted up perfect.

 

You should get a stall. My opinion of course.

 

Wow, excellent results.

I wouldn't upgrade injectors without tuning for them. Even the next size up 30# injectors are almost out of the adjustment range for the computer to compensate. If you haven't been tuned with your current mods I bet you could pick up even more getting that combo dialed in.

That's some nice times for that truck though.

 

That's impressive. Got my attention for sure.

 

Good info. I can guarantee you that you'll feel a huge difference with a good tune. Do a search here for guys swapping out the 99 PCM for 01 or 02 year models. The tune for those years is much better. Everyone who has done it on a 99 model agree - better throttle response, better mileage, more power. Get a custom tune based on one of these year model tunes and it will be even better.

 

I take it that being a 2500 it has a 6.0L? I would toss the HPPIII and get a custom tune mail order ecu. You will be allot happier.

 

I tried the Wester's tune before the cam swap and it made the truck slower and burn more gas, was very dissapointed that it could not perform better than the Hypertech.

 

man i wish i had my heads. they are suppose to be coming.

 

99 2500 - If there is anyplace out there(you trust) where you can get a dyno tune go there. A mail order tune is gonna be hit or miss with unknown combos, it's gonna take more than one try with a mail order tune to get things right.

I wouldn't take the chance with a mail order tune, I'd find a place that can dyno tune it. IMHO of course.

 

it was suggested to me that I should put Lingenfelter stage II heads on my truck. Anyone have any thoughts on that? dude claimed it should easily give me 75rwhp.