I will also add that the GM L8P crate engine is a L8T with a LT2 camshaft. With the LT2 cam and long tubes the power increases from 401/464 to 523 hp @ 5,800 and 543 tq @ 4,600. That is stout for a basically all stock GM small block.
If the L8Ts had been available for the price they are now with basically no mileage on them when I built my 383 my 97 Express would likely have one in it instead of the 383 backed to a 6L90E or 10L90E.
This is the L8P dyno chart. Again nothing more than a LT2 camshaft in a L8T and long tubes. Even with accessories on it this would be around 500 crank HP.
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This is what a LT2 cam cost. Huge gains for such a modestly priced cam upgrade.
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