I have an L33 in my work truck. Supercharger went **** up, so now it's n/a. It has mildly ported 243 heads, stock truck intake manifold, long tubes, and a 218/230 118 blower cam. It made 331/320 on a dynojet. That's through a 4L80 trans.

 

Thanks again everyone.

G Atsma..... I had read somewhere 15% was just a general "rule of thumb" for manual transmission cars when converting fwhp to rwhp. 20% was the same general rule for automatics. I'm sure it's much more technical than that though.

I do have another couple of questions to ask but if you all think it would be better served in the Gen III forums I can ask over there instead.

1) I am going to move the engine as far back as I comfortably can without having to do any "surgery" on the firewall. Maybe a little "massaging" but no cutting and welding. I think the L33 has at least one sensor (crank position sensor?) mounted on the rear of the engine. Is this going to cause any problems? Can it be relocated? Would a true Gen IV 5.3 (LC9) be a better option for a tight rearward fitment? The T-56 Magnum has multiple shifter locations so this may not be an issue, but the farther back the better for weight. There may be a shifter location that allows for a very rearward fitment and still have access to anything on the rear of the engine that I might need to get to. The new combination will be about 200 lbs heavier than what is coming out. I'm going to have to go with a custom driveshaft anyhow so no worries about transmission to rear end length.

2) With Jr. College and all (not to mention a new "family dynamic" ) I'm not so much on a "limited budget" but a limited time:money ratio if that makes any sense. I'm not going to go cheap just to get done, it's just going to take longer to save for quality parts. Two things dad taught me......Plan the work and work the plan and if you can't afford to do it right the first time, how can you afford to do it right the second time? So, that being said, my head choice is the 243/799 and a good mid range cam. (wish I could find something like the "Triple 12" I've been reading about). But let's say (for S&G's) that I want to go with a small turbo build 3-4 years after I get it on the road. Something, that I can do myself as my skills get better. Am I better off keeping the 243/799 heads and adding a turbo years later, or is the compression ratio too high with those heads? (And what about turbo and flat-top pistons? Good or bad?) Or should I go with a lower compression head (706/862) right up front and and enjoy them N/A and be "ready" for a turbo upgrade if I decide years later that that's what I want. I know I asked something similar to this and have taken that into consideration and I am hoping that I can keep the 799's and either add a turbo to it or that the cost of changing heads at a later date is minimal. I don't know (because I don't have the practical experience yet) if even though the 799's may be less money up front (comes with the long block purchase), it may be more money in the long run run because I will have to buy a second set of heads if I end up changing my mind later.

If any of you don't understand, this is the kind of mental frustration you have to deal with when you have OCD! It can be draining. I'm not looking for a definite answer from anyone, just solid opinions that I can weigh against each other to try and make as an informed decision as I can. Ultimately it's up to me to make the final plans and again I'm just about there. I like reading the build threads on here and using that information to help make decisions. Sometimes it becomes information overload, but they have been helpful as have all of you.

Thank you again for your patience.

 

For mild boost (less than 14ish psi), 10:1 is really good. No sense in going lower. Find you a cam that will play nice n/a and with a little turbo boost. One of the cam guru's can set you up.

 

both 5.3L engines are very similar, chances are the LC9 will have lower mileage. Otherwise delete the DOD and as far as the VVT… if you’re running the factory ECM it’s doable but if you’re planning on using a aftermarket ECM. Most likely it won’t support VVT. Best thing is also deleting the VVT and install a BTR Truck Norris cam. You’re going to have over 450 hp at the crankshaft without losing bottom end torque . The 58 tooth reluctor wheel is just a more accurate measurement for ignition timing. You will need a 2007 or newer factory ECM for the 58 tooth wheel. The crank sensor is above the starter. If the sensor is gray, it’s a 58 tooth sensor. If the sensor is black, it’s the 24 tooth system. Aftermarket systems like Holley Terminator X max are system specific but available.