cross member modification

[GsxrMike]

So I was test fitting the crossmember on the frame rails today and it isn't going to work. My project didn't come with a drivetrain so I bought a th400 np203 combo with crossmember. The crossmember is a little to short to make it all the way to the holes in the frame. It is the cross member that has two tranny mounts and connects to the adaptor. Didn't know if anyone had done this before and had some advice. I was thinking about getting some 1/4" plate and extending the cross member. Let me know if you guys have any ideas or suggestions and let me know if you need pictures. Thanks!

 

[thatK30guy]

Pics of the crossmember and the adaptor being used to mate the tranny and case, please.

 

[GsxrMike]

Here are some pics...

 

[NewUser]

same crossmember/transfer case/adapter i have in my 77...only diff is i have a TH350 and not a TH400 and it lined up perfect on my frame rails when i put it back in

 

[GsxrMike]

I'm putting mine in an '86 K5!

 

[NewUser]

i wouldve thought the crossmember would be the same between the years but maybe not?....what year did the crossmember you have come from?

 

[thatK30guy]

I'm putting mine in an '86 K5!

Theres the problem right there.

Your 'member is the flat kind, '84 and older on all K-trucks. '85 on up to '91 used double-hump 'members. Even the mounting holes are different between all of them.

Using a 400 tranny will put the 'member back slightly more than a 350. You just need to simply drill new holes after you get everything buttoned up to the engine.

 

[obijuan]

but he says the frame rails are too wide for the xmember, i hope i dont have that problem!

 

[GsxrMike]

Right, frame rails are to far apart. The cross member still touches both frame rails but I am not comfortable with the amount of over lap on each side. The farther back I go the worse it gets. I was hoping someone had done this before and came up with some thing cleaver to make life easier. Otherwise I am cutting and welding and grinding and painting and cursing! And to make it worse I have to do it all with the motor and tranny in because I don't know where the cross member is going to end up.

 

[blazin_blazer]

so the same adapter for 350/203 as 400/203?