Mid-plate adapters....

[Mcstiff]

What does it take to make one? Just find center and drill holes? How about if you want to use one as a mount too? Thinking this may be an option for joining the TH350 and Buick 3.8 when I start building my CJ6 again.

[cagedxj]

check out some of the drag racing fab shops. They are so cheap that it is almost not even worth making your own.

[Scott@Rockstomper]

In theory, as simple as overlaying both bolt patterns around center and drilling a bunch of holes.

In reality, I think the alignment is supposed to be within about 3 thou, or it'll have transmission input bearing/bushing issues. The drag guys actually have offset dowel pins and dial-indicate their bellhousings onto their engines for accuracy, using the offset dowel pins to adjust center. If you used something like that, you could accomodate some off-center-ness in the machine job.

There's no issue with using the mid plate as an engine mounting location, but I'd recommend pairing that with at least a front mount if not a whole front plate like what's done in drag cars. A lot of drag and roundy-round apps actually run with solid front and mid plate engine mounting, and no transmission mount at all (not a good idea with a transfer case hanging off the back). Otherwise, you're potentially putting a whole lot of crazy loads on that mount (and/or the tranny/transfer).

I'd think that for a Buick 3.8 to TH350, a stock app setup should be readily available, that doesn't need an adapter at all, just a specific tranny case. Assuming that's the case, you might be able to get a mid plate for a 3.8 app, but considering that mid plates are pretty much just a race-use item, and a 3.8 isn't exactly a common drag or roundy-round engine, I don't think you'll be likely to find an off-the-shelf mid plate for it.

[Mcstiff]

I all ready have a mid/adaptor plate actually, orig app sprints or something. I guess I was asking more about midplate as a mounting point. I am still planning on having a tcase mount (205). The reason I have a conflict between the TH350 and a Buick 3.8 is because it is a FWD S/C'd GTP 3.8 not the older version. The other apps are some 4 cyl S-10's and some 727's/904's (still an option now that I think I am dropping the 203 doubler idea)

[Scott@Rockstomper]

Gotcha. I see no problem with mid mounting it, but I'd do it as a semi-redundant setup, if it were mine. At least a support mount at the front of the engine, and a support mount at the tcase adapter as well. You can safely dump your entire torque reaction into the midplate, I just wouldn't rely on it (and, by extension, the bellhousing) for all support duties with only one other mount either at the back, or at the front.

[cagedxj]

Id support the front too. Just remember that if one mount is solid they all need to be soild or vise versa.