Engine angle for SBC in Avanti II

[RQ-B1899]

I would like to know the engine angle of a stock small block Chevy engine in a 1972 Avanti II.

I recently put a ZZ383 and a Tremec TKO-600 in my car and I don't know if my engine angle is correct.

Thank you in advance for this information!

Terry Stinehelfer

Bucyrus, OH

[Gunslinger]

I don't have the answer but with that engine/tranny combination it's gonna scream!

You can get the upgraded motor mounts from Nostalgic and go with it. That's what was done with my '70 and there were no problems at all. I have a GM 350HO 330hp crate engine with a 700R4 and aluminum driveshaft...it can smoke the rear tires all too easily so you might have trouble keeping tread on your rear tires!

[Ray K.]

Generally speaking, you want the the universal joints to have zero degrees of angle when the car is on level ground. There should be a theoretical straight line from the center of the harmonic balancer through the center line of the crankshaft, the center of the transmission output shaft, through the center of the driveshaft, and the center line of the pinion. The angle of the driveshaft to the horizontal should be the same as the angle of the engine block (crankshaft) which should be the same as the angle of the differential housing (pinion shaft). The exact number of degrees is not as important as all measurements being equal.

[BobS]

Terry

My 83 with new mounts ( motor and tranny) 26" dia rear wheels, 24" dia front wheels and standard suspension setup has a 3 deg drop to the rear of the engine at the carb top/air cleaner.

My engine builder says my 355 SBC should be about 400 hp tied to a stage II 200R4 tranny and 4:10 Auburn pro series posi with 8.5" of rubber on the road. At 2200 rpm of the line I get some wheel spin but it hooks up great, however, above 2700 rpm off the line it will just eat rubber. Your 6-speed manual should respond much the same with to much rev's off the line.

I don't know driveline dynamics well but if I recall, the engine/tranny, driveshaft and rear end should not be in a straight line. The u-joints need a couple of degrees to work in to function properly. The centers should be on parallel lines.

Sounds like a fast ride.

Bob

Edited July 2, 2010 by BobS

[profaqualung]

RQB1899

I'm getting a late start on this one, but let me throw my 2 cents in anyway.

I installed a 494 horse 383 SBC couple to a 700R4 in my 70 Avanti II. It immediately became apparent that the weak link was going to be the Dana 44 pegleg rearend. Invested in a 9" Currie [with Explorer discs on the back] to cure the problem.

They recommend a 5 degree down setting for the rear end - the Dana that came out was 4 degree down.

If you do a 'search' [Currie 9 inch] on this forum, you will find a complete list of what I ordered and its specifications.

One other tidbit - I had to go to 16" rims [Magnum type] to get tires that were 180mph speed ratings.

Thomas