[mr48chev]

It takes a bit of jockeying and you might have to set the crank centerline a few frog hairs lower than the crank centerline of the six was to get the trans to clear without mods but it can be done. Or you may just have to modify the trans cover a bit and not the floor or firewall if you work it right.

I'd consider working from the trans mount to the front rather than trying to get the motor mounts set and then figure out the transmission mount.

You might want to mock up a transmission crossmember by clamping a board or piece of channel or what ever angle or tubing you have available that is long enough to use and set the engine and trans in and mock up where you want the trans to be. You might have to use something as a spacer to lower the mockup crossmember a bit. you really aren't gong to set a lot of weight on it but it need to be somewhat solid so you can figure out how high you want the engine in the front. Then it is either draw up the plans to fab a crossmember or shop though the universal transmission crossmember listings to find one that has the right drop aka right height for the trans mount to bolt to..