I've had the LT1 in my IROC for nearly 6 years... to say the least, it's seen better days. I had planned on a complete overhaul of the motor - 383 forged stroker, ported stock heads (285cfm) & intake, and custom turbo kit (68-72mm.. haven't decided). In addition to the motor work, I will be overhauling the front suspension with the complete spohn tubular k-member, a-arms, caster/camber plates etc.

Additionally, I'll be receiving a brand new WC T5, free labor, and nearly all items at cost (except for suspension) due to bartering services over the years. The total to do the above mods will be around $9000 (high estimate) when it's all said and done. For roughly the same price, I could swap in an LS1/LS2, T-56, full exhaust and suspension... there would be no power adder.

Obviously there are pros/cons to both setups, but I'm extremely torn. A turbocharged LT1 making 600 rwhp is impressive, but the aftermarket and weight savings of the LSX is undeniable. So, help sway me in a direction.

 

My thoughts -

1. Turbos like automatic transmissions.
2. If you have a lot of boost with the LT1, you will need an aftermarket pcm and it would probably piggyback the stock wiring/pcm you have. There are aftermarket pcm that make it so you don't need an opti at all, instead use coil pack system. Another plus over all motor would be better exhaust clearance.
3. If you want all motor then go with the LS1, if you want forced induction then stay with the LT1.
4. Yeah the aluminum-block LS1 weighs less, but I wouldn't want an aluminum LS1 if I was making serious power. I would want an iron LS1. Not a lot of the weight savings I would imagine with an iron block.