We had another customer point out this post and need to set a few things straight.
1. We are working with Rollie to find out what is not working and a fix. We have sold quite a few of these with no issue other than the "other" caliper issue. Rollie did not put in the other spacer - hence it will affect the fitment. The rotor may also be undersized in diameter as evidenced by the picture.
2. Some of you seem offended that we do not feel that tapping the existing holes on the spindle is a good solution and point this out in our advertising. I did not mention Rusty Hope by name in this ad; there is at least one other supplier for this application that requires you to tap the holes (and do some heavy grinding on the spindle). We were called in by a local rod shop after they tried to use the latter kit and it failed. They asked us if we could do better. We engineered a strict bolt on - no grinding or tapping (and since this load is almost all shear, 0.105 of grade 8 bolt is much more than enough to do the job). Back in the early part of the last century hand cranking a motor was the norm, with the possibility of injury or death in the event of a backfire. Do you think when the self-starter was perfected it was not touted in advertising?
3. We got beat up on Moparchat.com a few years ago for using GM calipers on a Mopar application (1962-72 B and 70-72 E bodys). We then changed the design to use 1994-99 Ram calipers; and customers whined the parts were too expensive. So I decided to hell with it and use whatever works the best. We have a large inventory of calipers and rotors of all shapes and sizes, from 1969 GTO to 2005 Mustang. In this case we found the 70-74 E body caliper works best: compact, excellent hose routing and it is Mopar - only drawback is it runs about 20 extra per unit - and availability unlike stated by others it is next day at your nearest NAPA or rockauto or partsamerica or autozone or...
4. The phantom caliper. Since I talked to dezeldoc I checked and am still undecided. Hollander, Raybestos, NAPA say unh-uh - 70-74 E are the same. But Hollander shows the 73-74 spindle to be different (?). And I have a March 1980 dated Wagner brake book that shows a 70-72/73-74 split. Without the two different pieces on my bench I withhold judgment. Neither of the two E body guys I know (one a professional restorer) buys that they are different - but in the sales of almost 5000 conversion sets I have seen weirder things...
5. The customer is not always right. Hence we try to make our stuff as foolproof as possible - but as we said in the Navy "foolproof doesn't mean sailor-proof". We do make errors and try to get to the root of the problem with the customer then fix it. We kaizen our stuff; always looking to improve the product and instructions.
I believe that is enough for my first post.