Weighing my options

[matttahoe53]

Stock L31 is 9.4:1 and it runs 87 just fine. Aim for the same and you should be alright. You are going with the roller block right?

I've been researching this too for a while now and am going back and forth between an LQ4 Gen III motor or a L31-383. Stock LQ4 will be about the same money, if not less, then building an 383. It will get you at least 300HP and 360 ft. lbs of torque. right from the get go. Then when you have some more cash and know what you want, get a bigger cam, headers, and a tune, and you'll be stearing down at about 400 HP and 430+ ft.lbs. of tq. with ease. More so if you go the L96 head route and Corvette intake, but then you'd have to change your accessory brackets too.

Why I suggest that is because of LSx engines being easier to work on, being able to put down more power with less cubes, and being overall more efficient. You can build a 383 from scratch for about the same money you'll put in the LQ4 with a swap and a few go fast bits and end up at the same power levels. LSx will be more efficient, but the 383 will be all freshly rebuilt. Your call really.

Yep I have a roller block. I know I should go with a ls engine, but for me I think going the 383 route will be easiest. I am aiming for 10.1-1 to 9.75-1 compression. I won't be too upset if I have to run 89. Now if there wasn't any ethanol in our fuel...

 

[matttahoe53]

Is anyone on here using the world products torquer head? It looks like a pretty quality head plus it's one of the few available that have a 76cc combustion chamber with a smaller intake runner of 170cc. I think this would be an ideal head if it works with the vortec intake. I've been searching around and I can't find if these work with the vortec intake or not I assume they do but I want to be hundred percent. With that 76cc combustion chamber I could possibly run run flattop pistons with four relief valves and keep my compression low enough to run pump gas.

 

[Tavi]

Compression ratio is not a black and white answer. There are far too many factors that go into what is safe. Head material, operating temp, quench, air fuel ratio, timing, and possible hot spots inside the combustion chamber, too cam duration. The more cam duration. Lets you run more compression.

I'm running a 355 at close to 11.3:1 compression on 89. With no detonation. I also have aluminum heads, lots of duration, mild timing, and the engine doesn't get over 170.

The world torquers look like a good mild performance head. With a little work stock vortec could be machined to similar specs.

I would put my money into a torquey cam, tune and gears. You mentioned not wanting to do gears. But it will make a totally different animal. And even a stall converter if you go much bigger on the cam. The stock heads can be worked over to make some real power. Don't discount them. There main drawback is the amount of lift they can support. But a competent machine shop can fix that.

 

[matttahoe53]

Alright I've got the PCM swapped and everything is running a little bit better now. I even activated the tow haul switch which will be a nice feature when driving through the mountains, the truck can be kind of a dog trying to get up the mountains and it's tough on the transmission with the larger tires. Tonight I will hopefully install the efans I am just working on putting together a wiring harness that will control them through the PCM.

As far as my thoughts on the swap go I found that the throttle response is a little bit better, shifts are a little bit smoother, and idle is a little more stable. Add to that the tow haul switch which will be very useful and I thought I would never use it and the ability to control the efans this was a great mod to do.