60->78 crossmember swap really tight

[60 Apache Shorty]

I need some help. I have a front crossmember out of 78 C10 all freshened up, new bushing/bearings, drop springs, drop spindles,, conversion rotors its painted and ready of install. The 1960 crossmember has been removed frame rails are in final stages of getting cleaned up so I thought I'd do a dry run. It looks like the 78 crossmember uprights are about 1/4 to 3/8 narrower than the uprights on the old crossmember. I've seen some great posts on here about reusing the top rear bolt hole I'm just not sure how I'm going to get it back that far. The frame gets wider as it goes back. At best loose fit I'm about 2.5 -3 forward of where I want to be. Looking for suggestions. Will things flex enough to get it to that spot?

At this point the front of the truck is resting on jack stands and I'm using a motorcycle/ATV jack to raise up the crossmember. I don't want to jam things too tight here as its just a dry fit before I paint.(was hoping to get holes predilled now) One thought was once everything is painted put the truck weight is on the crossmember fwd of its final resting spot then use as come along or something to pull it back, I'm just not sure I'll get it where It needs to go.

[SkinnyG]

It was a curiously tight fit fitting an '84 'Burb front on my '61. I did (and recommend) moving the crossmember forward 1".

There will be enough flex to make it work. Don't over-think it (grin)

[Mikemelton]

I had trouble with mine but it was a bare frame and had been hanging from an engine hoist I put a ratchet strap between the rails and tightened it down a little until it dropped in place. Not saying it is the “correct” way but it made life easier for me and it worked

[60 Apache Shorty]

I ended up putting a come along around the frame and giving it a little squeeze that made all the difference and I was able to wiggle it in. I've had it in and out a few times now getting all the holes drilled and lined up. I've tried again with out the squeeze and its a no-go. I found a spot that the front 2 lower bolts matched up. The wheel looked good to me front to back in the wheel well so that was the position I worked off of. shock mounts for sure are not lining up so factory 60 mounts have been ground off and that is this weeks project to get them relocated and paint the frame so I can get this crossmember mounted final/ final and move on to getting the motor mounts and trans crossmember positions figured out.

[MT65]

Guess I got lucky, my frame was painted, the 86 crossmember was painted, used a floor jack and put it in place within half a hole, used an alignment bar on the holes that are the same with minimal effort….