90 k5 205 swap a few Q's

[brooks294x4]

so the 205 with fitzall spacer is in, being supported by a steel bar form rail to rail, heres where i need some help, searched and didnt quite find what i need.

is there a crossmember for this setup, or will i need to fab one?

i know i need a longer rear driveshaft, dont think i do, but will i need a new front one?

oh yea specs are 90 k5 350/700r4/205

 

[dyeager535]

What adapter are you using? "short" or "tall"? Short needs one of the "humped" crossmembers, tall needs the flat crossmembers.

I know there is a post on here with pictures of all of them. I know you searched, can't think of any key words that stick out in my mind.

 

[4X4HIGH]

AFAIK you need to make a custom crossmember. The 90 blazer never came with a 205 and the later blazers have a wider frame than the earlier ones so an early crossmember won't work without cutting it in half and welding in some material.

 

[brooks294x4]

i kinda figured on the custom crossmember, and cutting the stock one was exactly what i was gonna do, and just redo the mount part so i dont have to worry about driveshaft clearance

 

[dyeager535]

I'm confused. I've got a 205 in my '85 K5 using a stock crossmember. What are you doing that is different?

 

[4X4HIGH]

Dorian, there was a frame width difference but i don't know when that change took place. It could be that the change took place after 85 and that's why a stock crossmember worked for you? I'll bet the change took place when a couple of the body mounts moved to the outside of the frame whenever that was.

 

[dyeager535]

My frame is an '81. I had the "early" flat crossmember 465/205 10 spline combo in this truck, and I now have a "later" humped crossmember with my 465/205 32 spline combo. Both of those are '81-later pieces.

I could NOT use a pre-'81 crossmember, as the frame difference WAS too great between the two. The pre-'81 crossmember did not overlap the frame rails far enough to run bolts through.

In a '90 K5, all but the pre-'81 crossmembers will AFAIK work, but depends on what adapter you have as to whether you need a flat one or humped.

This is a post with a picture of the "flat" style I used with the tall adapter:
http://coloradok5.com/forums/showpost.php?p=2207757&postcount=3

 

[brooks294x4]

that flat crossmember looks like it would work, as i have a 2'' spacer from fitzall and a stock th350/205 adapter. it looks like i might have a slight driveshaft issue using that crossmember though. i did just go buy some 2x2 .250 wall tube to redo the stock one so im probly gonna go that way, but id like to see what years could possibly work, as i junkyard hunt alot. i will keep posted on the crossmember build.

 

[WJACKSON11X]

Subscribed. Going to do this eventually

 

[brooks294x4]

will start cutting metal to do crossmember tomorrow after work, already bought plate, hardware, and all that other **** ya need

 

[brooks294x4]

so i took all my measurements and am ready to start building, torches were out of oxygen so i couldnt cut today, but heres what its gonna be.

2x2 .250 - will need ~5ft. bought 6ft $20

bolts, nuts, lock washers - $5

2"x8" 3/16 plate - freebie, had it laying around

mining belt for mount - freebie from a coworker

so i should have about $25 in it and well say 2 hours in mockup/fab. will get pics as soon as its cut and ready to go

 

[wayne]

I put a th400/205 in my old 89 K5 with a stock crossmember. I would 3to1 that 205. Stock low range sucks compared to the 241.