crossmember swap questions

[musbrad]

Howdy folks,

I recently purchased a 1972 blazer 4wd, going to do the evil 2wd swap and airride. A friend has a 77 crossmember with drop spindles etc, from what I've been told, there are no holes that match from the 4wd frame to the 77 crossmember, do any of you guys have the correct dimensions from specific points where I can make sure I'm putting the crossmember in the correct position? I have a SWB 2wd C10 frame, I'm assuming I can use that to check, but if any of you guys have the info handy, I'd surely appreciate it.

Also, do the blazers have a 2 piece driveshaft or single shaft?

Thanks in advance

Brad

ps i've used the search function, but no specific distances have been given.

[N2TRUX]

Welcome to the forum musbrad. From what I remember the 72 Blazer should have "some" not all of the holes required to do the conversion. Take a look at this post by Gringoloco for a nice build thread on a 4wd Blazer "How to: Ruin a perfectly good Blazer..."

[tubbedII]

The link to gringoloco's thread posted above doesn't seem to work (takes me back to this thread), but here's a link to it: http://67-72chevytrucks.com/vboard/s...d.php?t=264654

I don't ever remember it talking about the front install other than the dropmember upgrade, so if you go with the 77, I'd mount it where it centers the wheels in the opening (about 1-1 1/2" forward) since you have to drill some holes anyways. Since I've never done this personally, I would think you have to take the steering into consideration since the center link is already very close to the crossmember, but maybe someone else can confirm this.

An easy way to get the crossmember centered is to mock it up with the spindles on and then line it up with a plumb line from the center of the wheel well (fender on obviously).

My blazer is a factory 2wd, and it has a 1 piece shaft...can't say that's factory though since it's been gone through a couple times.

[SCOTI]

I think the steering will dictate where things go. The steering box, pitman, & idler arm are fixed on the front sides of the frame rails. Get those in place & connect the steering linkage (center-link & tie-rod ends). Move the x-member into position based on the tie-rod ends being square w/the steering arms on the spindles.

I'm not familiar w/the 4x to 2x swaps but would guess the main front x-members would most likely be on the same wheel-base centerline & thus share some existing frame holes. Definitely worth a shot. Gringoloco did the Dropmember swap on his & they install using factory holes.