motor and trans swap

[trick]

Hello, I have been given a 351C 4V motor and C6 trans. I would like to swap my 390 out and drop in this set up. I looked at other topics and the frame mounts that i need are for the 302. but they say that it sits 1" lower in the frame. My question is what about the trans mount. Do I get that from the same frame as the 302 or do I need to modify my exsisting one 1" lower. I want no driveline problems. the truck is a 69 SB lowered 3" in the front and 4" in the rear. My 390 is getting tired and I thought I would try something different. I have no problems with the truck now. Thanks for your time, trick

[FORDification]

The motor mount hooks up to the block in different places each of these two engines. Putting a 390 on small-block stands will put that 390 an inch lower, but the small-block will sit exactly where it's supposed to on the same stands. Therefore, your existing transmission crossmember will still work.

[trick]

This is from you site:The 302 stands are 1" lower in overall height than the FE/I6 versions, as evidenced in Figs. 1 and 2. Also, the flat portion across the top where the motor mount sits is about an inch wider and several inches longer. However, once they're bolted up to the frame and crossmember, an FE will bolt up to them just fine....your engine will just sit 1" lower. You should still have plenty of oil pan clearance. This would be a great mod to help lower your truck's center of gravity for slightly better handling. However, you COULD have driveline angle problems, due to dropping the engine 1" but not dropping the transmission a similar amount.
Conversely, bolting up a 302 using the FE/I6 stands will cause your engine to sit 1" higher and I've been told this could also cause problems with U-joint bind due to improper driveshaft angles.

Should I use the 302 stands or the FE stands that I'm curantly using now. I'm but I'm worried about the trans mount and driveline angle with the lowered truck. trick

[FORDification]

You're wanting to swap in a small-block....which means you should use the small-block stands. The ride height of the truck has nothing to do with which set you use. If you're asking what I think you're asking, it would be impossible to drop the engine/trans down far enough where it might drag .

It's as I stated in that article...If you mount a 302 on FE stands, it'll set an inch too high, meaning you'll also have to shim the transmission crossmember up an inch to maintain the driveangle angle. Conversely, if you mount an FE on small-block stands, the engine will be an inch lower than it should be, meaning you'd have to figure out a way of dropping the crossmember by an inch to maintain the proper driveline angle. Since you're swapping in a small-block, just use the proper small-block stands and bolt everything up...no worries.

[trick]

thank you, I was worried about the trans mount being an inch to high or to low, or make my own. trick