Re: Engine sitting too low??
Steiner... Steiner... Steiner...
Yes, you forgot a couple of important factor's. The heights are all at 45°. The frame stands are not being changed so you leave them out of your math. The difference in height is the difference between the "tall and narrow" and the "short and wide" engine mounts. This is 1/2" at a 45° angle which = 1/4" in vertical height.
Now, as you have said the "short and wide" engine mounts will not physically bolt between the 302/350 mounts as the distance between the thru bolt holes of the frame stands does not match the thru bolt holes of the engine mounts. Depending on how they oblonged out the holes in the 302/350 stands is really going to determine how much the engine will be raised. The OP said that he needed the fan to be 1" higher. I only see 1/4" to 1/2" at the mounts. Hopefully that 1/4" to1/2" at the mounts, with the transmission mount at it's original height, will make enough of an angle to raise the FAN enough to clear.
If it does not, then lower your tranmission mount by using a thinner mount.
69 Camaro -originally a LM1 car. 327, Edelbrock E-streets, hooker, DUI performance distributors, ultradyne cam, stewart, TRW etc. Vintage Air, AGR steering, Corbeau GTSII seats, 700R4 transmission, 12-bolt w/Eaton 4.11:1