since i plan on running my lt-1 to a 383 and dropping in a hotcam with a flowmaster exhaust and lightly plained head and smooth exhaust ports with LT headers, can i expect a huge drop in gas milage(6-speed highway driving) and streetability? I really dont want to have to run premium but do i have to?(ECU will be redone for the mods)

 

Hell, most people run premium in a stock f-body, otherwise it will knock and the computer will pull timing, thus reducing power

 

isnt that a little long for stroke? I dont know, but ive heard that you should have anything bigger than 3.75"

 

GM actually sells a crate engine that is 4.00" bore x 3.80" stroke, and calls it the "HT 383" (although its actually a 382.02).

And no.... 3.75" is not the limit for stroke on the LT1... many people run 3.875 (396), there is a 409 short block available with a 4.00" stroke, and Mark Montalvo built one of his "421's" with a 4.125" stroke. Not really cost effective to go much over 3.875" though.