Im looking for some advice/reccomendations on my build. I have yet to build it as i am still in the planning/research stages. Let me start off with what i have.

I have a 2001 gmc sierra c3. It is awd with a 4l65e and a lq4. I am looking to get as much low end power and fuel economy as possible. Thw reason behind this is i will be driving across country towing a travel trailer 4000+ miles from alaska to new england.

I am currently leaning towards the tsp 224r cam. The specs are .224/ .224 l, .600/.600 110 lsa. With the cam i plan on running 7.4" pushrods, new ls7 lifters and pac 1218 single beehive springs. I am inexperienced when it comes to lift/duration and all of that but i called and talked to them and they said the cam would make good low end power.

I am also leaning towards american racing header's 1 7/8" primary headers with 3" collectors along with their catted connection pipe.

I have been doing some reading and it seems like people tend to favor a set of 243 heads on the lq4 for the compressiom bump. Is this worth it stock vs stock, or do the 243's have to be ported and polished/ decked to notice a difference? Also, will i have to change my intake to accomidate the 243 heads?

 

224/224 cam is to big for towing! Way to big for mileage.
I would get a Cam Motion Drop in truck cam, 6.0 Stage 2
212/218 considerably smaller! Porting the 243 is Good!
Milling for comp will require premium fuel. I would
also consider getting the FAST LSXRT Truck and having
Tony Mamo port it.
Ported 243s, the right cam, ported Fast intake, and ARH
Headers ( I would talk with Nick @ ARH also 1 3/4"
May be better for your primary operating range
1500-3500 RPM and goals Towing and Mileage)
I would expect at least 35-50 lb ft of torque in
Your operating range And Better mileage at cruise.
Just my .02

 

I definitely agree with him, from my personal experience with the 228r. Albeit larger than what you were looking at, it isn't much larger. And I personally have mine in 4200lb B-body.

 

Thanks for the great info. A new intake would be nice but that might break the bank. After the cam amd headers, i might have money left in my budget for the 243 heads. Can anyone shine some light on the 243 heads? I am currently in alaska and can only get 90 octane. What can i bump my c/r to before i start noticing detonation?

 

I would not exceed 10.0:1 Comp and tune for 87 Octane.
Also Ported TBSS Intake by Peak Speed is a great bang for
Buck, less then 1/2 the cost of an unported FAST LSXRT.

 

What part of Alaska? If you stick with stock thickness headgaskets, bolting on unmilled 243 heads should give you right at 10.0:1. This is what I'm doing with my LQ4. The cam is where you'll notice the biggest gain. You can reuse your stock intake without issues.

If you want the most low end torque, I'd forego the headers in favor of keeping the stock manifolds, as they flow better than you think, and doing duals instead if it suits your budget.

 

Anchorage

 

It seems like i am going about this build all wrong, and asking all the wrong questions. So im going to ask a better question. If you had a budget of $4k with low end torque and fuel economy as your goal, how would you build it?

 

Honestly, since you're looking for towing torque plus fuel economy (and assuming reliability since you want to make your destination several thousand miles away), I'd be leaning more towards a bolt-on Procharger system. Plus, you already have the advantage with the lower compression dished pistons of the LQ4 to run boost safely. Your $4K budget would get pushed with a brand new system, but a complete used kit should easily fall within range.

 

small turbo, stock truck manifolds, stock flex fuel injectors, pretty much stock everything else. Should be able to do it for less than $2000 if you can weld it yourself.