[Drsagacity]

The lt4 blower isn’t detuned in any way. If you take the stock lt4 blower, you will be in the 600whp range. Problem is the Lt1 fuel system. You will see the fuel drop off so you really need to either dial back boost with a bigger pulley or you need to upgrade the fuel system. The high pressure pump is first, then injectors and low pressure pump. You can simply get lt4 components and you are good.

With the upgraded fuel you are good for 600-650whp. However, the cam limits fuel so next you need a cam with a larger fuel lobe. This is when e85 becomes really useful. With the Lt4 fuel and the cam, you are good to run pump e85 (e70) up to about 800whp.

I would add forged pistons into the mix if you are going to push beyond 650whp...but I prefer less risk.

So short version:
1. Lt4 runs to 550whp on stock system
2. Add fuel: hpfp, lpfp, injectors and maybe Voltage booster - good to 650whp.
3. Add cam, pistons; lt headers: 700whp is easy (8psi or so)...but good to run higher...you will find the limit of the smaller blower in phase 3...