The Stovebolt Site Forums The Shop Area Driveline leveling for a IFS install

I'm installing a Speedway bolt-in IFS on my '50 3100. I have jack stands under the front of the truck near the firewall. I don't have any under the rear of the truck. The frame rails are perfectly level in multiple measurements. The crossmember reads the same, i.e., clamped in place. Given my measurements, is it necessary to put stands under the rear before drilling holes to mount the crossmember? If yes, school me as to why.

The reason for the four jack stands is to remove any spring or tire deflection which can happen if weight is added during the build. Bolting in just a bare cross member shouldn't cause a problem. We build frames/chassis from scratch so set up the ifs where the lower control arm (or A-frame) is parallel to the floor with ALL the weight on the vehicle. This along with correct Ackerman, anti-dive angle,correct caster-camber-toe in makes a good driving ride. If you chose the ifs with the adjustable coil over springs-shocks then you have some snudge room when completed.

coilover...I didn't go with coilover shocks, however, Speedway includes ride height adjusters on the top towers. I would assume that they will give me the "snudge" room you mentioned. Since the crossmember at this time is clamped to the frame ready for initial holes drilled to mount it, (all crossmember surface properly contacting the frame where it is supposed to),centered where the original axle was I don't see the need to put stands in the rear. How much better could they make it?
One precaution I did take before I removed the front engine/radiator crossmember for modifications, was using some all-thread at the very front of the frame to avoid potential movement. It came in handy when positioning the IFS crossmember...I had to tighten, pull together, the frame plus or minus 1/8" to get it to slide in place. I haven't removed the all-thread yet. If all fabrication/positioning checks out, my way of thinking is it's a 70 year old truck...how more precise can I make it given what I have done?

Evan is giving you the correct method to follow. If you choose to ignore his advice and do things your way, whatever errors you build in will return to bite you where you sit after it's difficult, or maybe impossible to correct them. When I built and/or repaired round track race car frames, we not only supported the frame on screw-type stands in several places before doing any cutting or welding, we also used floor-mounted anchor chains to keep it that way.
Jerry

Coilover is a professional builder. He does this stuff for a living. I believe I would follow his advice without question.🛠 It’s yours so do as you please.