Just kidden dave,Any way Hopper no matter witch trans you go with spend the cash and buy a (BLOWPROOF-BELLHOUSING AND A DRIVISHAFT-LOOP )that are SFI-approved.Even if your ELCAMINO dosn't run 11.99et Iv seen 12.00sec street cars Granade a clutch and it's not pretty.and whan you do go in the 11.00's your one step ahead of the game and you still have both your feet and other vital body parts.since the car will see some street duty I would go with the 5 or 6 speed that way you could put like a 4:11 /4:56 some thing like that in the rear and still drive on the street,you will kill the gear once your in 5th and 6th.(FYI) when chooseing rear end Gear keep in mind not all trannys are geard the same.

EXAMPLE=GM-T10 4spd/1st:2.43 2nd1.61 3rd1.23 4th1.00
Richmond GM=6spd 1st:3.28 2nd 2.14 3rd1.57 4th 1.24 5th1.00 6th.76