So I know this has been beat into the ground but, I need some advise.
I have a 2003 Avalanche 1500 that I have slowly been modding. So far it has
a used 2004 LQ4 with with 01 LS1 heads. Stock cam, manifolds and 3 in Magnaflow muffler. I also added Pro Comp 1.8:1 roller rockers. The heads were changed because the previous owner did not change oil very good and I could not get the sludge out of the passages like I wanted. So I also added a TBSS intake and throttle body and the DrX convertor, got rid of the restrictive air box and tube for my own 4 in CAI. I have added 05 cooling fans and aux. fuse relay center and added the fan control with my HP Tuners. Transmission is a rebuilt 4L65e from an 05 H2. Shift kitted and stock stall with heavy duty allison stator (thats what the parts guy said, supposed to be for towing).

Now on to the question:
I tow a 21' sport cabin cruiser boat regularly in the summer and don't like to play catch up to mini vans at the stop lights so I want to add some heads that I recently had given to me. They are 862 heads that have 2.00 I and 1.55 E valves and full CNC port job intake qand exhaust. They look to be in very good condition and I will be getting a fresh valve job and minimum surface for good sealing.
I don't want to loose any low end ( it's not that great right now) but I don't really need anything over 6k either.

Anybody got some ideas?

Thanks in advance, Jeremy

 

The best towing mod I did was gears.
342 to 390s made a world of diff towing

 

Comp high lift 212-218 112lsa +5 advance.

 

I knew the gear topic would come up and forgot to mention the truck came with 3.73:1 gears from the factory. I've also considered going up to 3.5" exhaust I just haven't found a muffler that sounds how I like.
Thanks again for the comments, and please if anyone else has ideas please speak up.
Jeremy

 

comp cams makes some cams just for trucks.

 

I think the main thing is stick with a small cam like what Jake suggested and it should tow great. I have a lq4 with a cam similar as Jake suggested and even with 3.42s and tall tires it has plenty of low end.

 

Be careful trying to keep up with soccermom minivans while towing your boat with your Avy. Your 60E might commit suicide.

 

"might"

He's just kidding, there is no might, it's going to happen.

 

The keeping up while towing read wrong. Its the morning commute that the soccer moms seem to have more than I do. I think the 862's have too small a combustion chambers and I am going to have to reconsider head choice. I've also got a set of 317's that I am getting freshened up. I think I will get them milled .030" while they are at the machine shop to bring up th CR.
I talked to Richard at WCCH and he suggested something under 212 single pattern and a 112 lobe sep? I can't seem to find such an animal anywhere.
I found a Comp tri-power extreme cam 54-530-11 that has 202 I 212 E .507I .500E.
Anyone running said cam and how do you like it?

 

Thats getting a bit small with only 500 lift. You can always custom grind, if I were to only tow (not race) id build a 11-1 cr motor and run a 209-212 in the 550 lift range 112lsa with 5 or 6 degrees advance.