swapping 700R4 to a turbo 400

[3x2GTO]

I'm picking up a 1986 chevy short bed 2wd this week, this truck is a roller, but originally had a 305/700r4 in it. I have an excellent running 454 with a T 400 short shaft tranny all from a 1985 3/4 ton 2wd suburban. Can I use the stock 305 frame mounts with the brackets that are still on the 454, or should I use all of the 454 stuff together? I know to change the trans yoke and will probably have to have a driveshaft made, but what about the crossmember? Thanks!

[PGSigns]

You will need all the big block stuff. You may be able to slide your cross member back to fit the 400.
Jimmy

[Ziegelsteinfaust]

The frame may need holes drilled for the trans cross member, but that's not a big deal. Usually there are a few more holes then needed, but I play with earlier models.

What I like to do to trucks was slide the engine forward 1/2-3/4 of a inch when equipped with a large cap HEI. This way plug wires fit better, and easier to time the cap. Then tack the mounts down.

[3x2GTO]

Thanks for the replies, I'll take your advice and use all of the 454 stuff, good idea about giving the HEI some more room. I just got the truck home yesterday and was checking out the RPO codes, it originally had a 305 / 700r4 and a 273 gear, I bet it was real powerhouse!

[Bigdav160]

The square bodies had transmission crossmembers that used 4 bolts up the side of the frame and two in the lower frame on the other side, correct?

IIRC, there isn't enough room with cab in place to drill new holes in the side of the frame from the outside. I think it would adequate just to use two bolts on each side.

[3x2GTO]

This is my first time moving a crossmember on a square body to a different location, I was hoping it'd be double drilled to accommodate the turbo 400. I really want to install all of the bolts, so I may raise the cab up, if that's what it takes. I'll know more when I get under it. Thanks!

[3x2GTO]

I test fitted the 454 frame stands and mounts to the C10 frame, looks like I can get bolts in the tops of the frame stands and thru the frame, but will have to drill the bottom 2 holes. I did notice the 454 stands had 1/2 inch front to back adjustment on the burb frame, but the holes are drilled 1/2 closer on the C10, thus eliminating any adjustment. Are my 454 stands fitting as normal here? is it common place to drill the bottom 2 holes and not have any front back adjustment? Hope to get some info soon, so I can get the engine installed tomorrow. Thanks!

[3x2GTO]

Here's the 454 mounts on the C10 frame