OK, I thought part numbers would be easier for me because you said 47-55 and then said 41-55 and said "kit". All I saw was 47-54 pieces, not a kit and not the years mentioned. I think I see the pieces you are using and you have not received all the pieces yet. Some of what I'm going to say may be obvious and some has been said.
My observations:
1.Your truck is earlier than the fellows that have done it. I don't know much about a 1940 frame or suspension. I believe you are converting from knee shocks.
2. It seems like the lower shock mounts are fixed by how they mount. It seem they set up the angle of the shock.
3. I would measure and record the necessary dimensions and a bunch of other reference dimensions. You do mention bump stop already. Seems like the suspension "travel" is 4.25, plus or minus allowances.
You want to do measurements after all new or original springs, spring hangers, bushings and any other suspension components are installed, lubed and torqued.
4. You don't say if bump stop dimensions are at rear or front. I assume rubber is on the axle not on the frame? You are saying at ride height it's only 1 1/2 to frame?...and only drops 1 1/4 ?
My "Too Sense":
5. I would mount the lowers and the clamp the uppers to a temporary position that clears everything and allows at least 3 holes to be drilled thru frame, later on.
6. There is a math (trig) calculation that could be done to determine the actual shock travel at it's angle vs the vertical travel of the suspension. This would be a bit difficult. An interpolation of that can be done knowing that the angled shock travel will be less than the 4.25 vertical travel.
7. "At rest", meaning truck sitting on tires on the ground. (Ride height)
8. Shocks should be pre loaded to about 1/3 travel when mounted at ride height. This plays into your selection of a shock.
9. After choosing the shock(s), bolt them onto the mounts tight while uppers are still clamped. Adjust upper for proper bolting, preload, angle and perpendicular to brackets.
10. When all is good, mark at least three holes using the mounted/clamped upper as a drill template. Bolt up bracket with Gr 5 hardware. 5/16 or 3/8. UNC.
This is just a rough idea for though, without being there. This is a custom situation and takes some planning and thought as you know. Maybe copying newer conversions and parts will work OK, maybe not.
Last edited by bartamos; 04/04/2025 12:07 AM. Reason: typo/punctuation
