i have a 72' i boxed the frame on and am dropping in an LQ4 (LSX 6.0) and 200-R4 combo. I am using stock (O'reilly auto parts) motor mounts for a 350-454 size engine (2-3/8" width mounts), Edelbrock engine adapter for this car from summit (not sure on P/N, but ~$63 one), and factory 350 -454 frame mounts. I am having trouble finding a place where I can zero out with my protractor to get the engine/tranny straight with the driveshaft.

With the X-member frame mounts level and the engine level (leveling the engine on the top plate between the heads), the tranny seems to sit tilited up in the air and I really have to jack my rearend up to get the driveshaft to level out. When I zero on the tranny pan, the engine sits ~5 degrees tilted down, but the driveshaft is level at a reasonable spot. Where can I measure off to level the engine/ tranny cambo, and where is the best place to measure to zero off the frame? Or am I better off getting the X-member close then finalizing the angle when the body is back on and it is sitting at ride height? This is my first time, thanks for any input.

how does it sit when you just bolt it all down, including the trans mount?
don't worry about the engine angle relative to the body- you need to set the angle relative to the yoke on the rear end at ride height. the driveshaft will always be at an angle relative to the trans. in fact, if you set the driveshaft straight with the trans, you will put extra stress on the u joints for some reason or another. i'm sure someone with more experience will step in and expand on or correct what i just typed...

I don't believe that V8 engines sit level in the engine compartment. They're usually leaned backward slightly. That's how it is in my BB 70 Chevelle, and that's the way it was in my SB 73 Vette too. In my Chevelle, while installing my Mark IV BB engine, I had to bring the transmission tailshaft as high as possible (after bolting the trans bell housing to the engine, and with the motor mounts loose) so that there was only about 1 1/2" clearence between the front U-joint and floor tunnel, in order to the trans slip yoke facing at the same angle as the rear end pinion yoke was with the full weight of the car on all four wheels (I had the car resting on top of four wheel ramps to give me enough room to work under the car).

Even with the engine tilted far enough so that the trans tailshaft was as high as possible, the engine still leans backward slightly. It is NOT perfectly level. I believe that;s how it's supposed to be, since there is no way that I can level out the engine perfectly, without the trans slip yoke making contact with the floor tunnel. This is with a factory ride ehieght, factory floor, factory type motormounts, and TH400 transmission.

Look at the carb mounting surface on an intake. You'll notice it's angled, front lower than rear. That's so the carb sit's level because the engine doesn't.

Look at the carb mounting surface on an intake. You'll notice it's angled, front lower than rear. That's so the carb sit's level because the engine doesn't. Yes.

Thanks for the replys I'll get it close and finallize the X-member when the body is back on.