I have the sub frame out right now. When I am ready to put in the new motor, can I mount it to the sub frame then put in the sub frame? Or will this throw anything off? Does the sub frame have to be in and bolted up and under the weight of the car before I put in the engine? Thanks

it's a little easier to re-align without the motor and trans only because of the weight you will be moving around... but others here have done it that way...:innocent:

easiest way and allows for the most working space.
1. subframe and suspension
2. engine
3. sheet metal

It's A LOT easier attaching the subframe without the engine. ;)
Roll the subframe under the body. Insert the alignment dowels and bolt the thing in place.

The body generally doesn't move during this process. So if you're inserting the subframe crooked, you need to shift the subframe. The less it weighs the easier it is to shift.

Don't torque the core support bolts until you position the fenders on the car.

I haven't tried on a chevy but I put a Mopar together by putting the engine on the subframe first and then rolling it under the car...I wouldn't do it again. It was a LOT harder to line up the subframe w/ all that weight on it as was said. It took longer than had I done it the normal way. If you had a car lift to lower the body down onto the subframe that would probably be a very different story then...

It's A LOT easier attaching the subframe without the engine. ;)
Roll the subframe under the body. Insert the alignment dowels and bolt the thing in place.

The body generally doesn't move during this process. So if you're inserting the subframe crooked, you need to shift the subframe. The less it weighs the easier it is to shift.

Don't torque the core support bolts until you position the fenders on the car.



Along with alignment dowels I recommend you do the dimensional check as outlined in the Fisher Body book. I measured mine and checked against book prior to removing subframe (spot on) then after all work was done installed subframe and checked dimensions, moved it around a bit and was good. Both times my alignment holes at the body mount on the firewall were not dead on aligned.