I have those, for my setup, someone had already set it up for smaller bolts, so I ordered a similar type bolt in 5/8ths. Those wont go through the frame mounts and the spring has smaller ID bushings installed. But yes, for the OP starting from scratch that is what I would recommend building around.
Yeah I emailed speedway this morning and they said that kit wouldn't work. Thanks for the link you sent me and I appreciate your help.
Rusty1 I just found this thread. I plan to do the same swap you have done. I have a '52 DeLuxe fastback and I plan to swap in the front axle from '51 3600 truck. Did you use all the original leaf spring mounts from the truck frame? I couldnt really see the rear mounts on your frame. Thanks for sharing your info.
...the pics I posted were of my 37 Chevy coupe that came with parallel front springs, which I used along with the 37 axle with a 2 & 1/2" block to raise the front a bit. used 51 Chev pass. car front brakes.