Theres a lot of variables when it comes to track times. I only compare what ive seen at my local track and what ive run side by side. My brothers ss for the life of him couldn't crack 14.0 on street tires totally bone stock. Went to Englishtown and ran 13.4. no changes at all. Different track.. differet altitude and all the other variables etc etc.
Im not knocking the LT4 but Theres been a ton of bs about hp numbers over the years. There was one thread about how some were 370 hp even 390hp for a few %. SOrry but that is
. If a 390 hp Lt4 existed.. weighing in 200 lbs less than a zr1 we would see trap speeds over 116-117 mph rivaling c5 z06s. Just not happening. Ive never seen an LT4 factory fresh run over 110 mph without some mods like headers or gears intakes etc. My 93 trapped 104 mph stock. I knew a guy who hung out with us that we went to the track with in a 96 LT4 like I mentioned earlier and he trapped 107 mph. 104-107 mph is about 30-40 hp. Right on par with GMs ratings.
I can definitely see why the LT5 may feel slower at lower speeds. It has longer runners tuned for certain rpms. at part throttle and certain rpms it only runs on half the runners. It can make for a soggy feeling engine at low speeds. GM also didn't add any gear to it. For a motor making higher torque and hp it sure could have used it. On top of that it weighs 200 lbs more. all those contribute to the slower low end feel.