Stroking a 5.3

[Fastshivy]

Ok I am iced in again and have way too much time. Here is a situation I have been thinking about and wanted some feed back. I have always heard an under square engine is better in a truck for pulling power and the weight of a truck. i:e the stroke is longer than the bore is wide. If this is true why did they make the LQ9 over square with a 4" bore?
I am thinking of buying an 02 2500hd ext cab with high mileage. It has the 6.0L. My thinking was to buy a 5.3L from a bone yard, put a 4.0 stroker crank in it and bore it to 3.90 This would give me more cubes (382) and be under square. I could also build the engine while I am still driving the truck. I do pull heavy loads sometimes (about 15% of the time) in the mountains and can't afford the duramax.
The above would not totally kill my gas mileage like an 8.1 and still give me enough grunt to pull 9,000lbs up a steep grade. Am I splitting hairs?
Any thoughts on how this combo might work vs the stock LQ9?

[2500Ak]

Interesting concept.

[blackout]

This is exactly the motor i am building

http://www.ls1truck.com/forums/lsx-t...-build-up.html

Mine is nearing completion.

[SNEEKY]

if you already have the 6.0 stroke that. make it a 408 no replacement for displacement

[txarkitekt]

if you already have the 6.0 stroke that. make it a 408 no replacement for displacement

+1.

[blackout]

if you already have the 6.0 stroke that. make it a 408 no replacement for displacement

This would definitely be the way to go. Much cheaper too. The only advantage I could see would be that 5.3 blocks are dirt cheap for building a motor outside of your truck. That was one point I took into consideration when choosing how to do mine, but in hindsight I would have done a 408. But I am sure I will be plenty happy with my 383.

[kyhunter89]

i myself perfer an over square motor. its more in the gearing, stall. but for pulling thats a different story. hp and torque is hp and torque no matter how you get it. but for pulling it needs to be down low. definately go with 408 over stroking a 5.3

[George C]

if you already have the 6.0 stroke that. make it a 408 no replacement for displacement

majority of ppl that go 408 cant afford the proper intake/heads/headers/exhaust to see the true motors power potential so they see numbers smaller cube motors see

[RedHeartbeat]

that would be me! LOL

I wonder who makes the best longtubes that would fit my 408 GMT900? Don't want to buy a set and they not fit. Kooks fbody header are hard to justify but its a possibility if someone can prove they fit. A better port job than a stage 2 is obviously needed since my 408 was a turd when I was running the LS2/90mm intake and longtubes along with the stage 2 ported patriot heads.

[George C]

that would be me! LOL

I wonder who makes the best longtubes that would fit my 408 GMT900? Don't want to buy a set and they not fit. Kooks fbody header are hard to justify but its a possibility if someone can prove they fit. A better port job than a stage 2 is obviously needed since my 408 was a turd when I was running the LS2/90mm intake and longtubes along with the stage 2 ported patriot heads.

i got a ported fast 90 i could let go for right price but now with the 102mm intake i would use that with a set of TFS 245 heads, 240-250 cam, dual 3" with the big boy headers and let that boy shine. toss mad timing at it, lean that fucker out and youll see huge numbers from that