Planning to show this car some love in the next couple weeks. She has been resting out of the weather in my shop but I haven't done anything since bringing her over. I know the engine will run, the gas tank is good, the radiator holds pressure, the transmission shifts, and I have a nice interior, so it seems like the to-do list is pretty short, and mainly involves paint and wiring. The biggest obstacle: I need to get this rear end located - so that's item 1. How can I be sure I've got the pinion angle right before I burn the spring pads in? I have no idea how to measure this. I understand the transmission output and pinion need to be on the same plane... but I'm not sure how to take that measurement or apply it to a finished product.
Off the top of my head I would you could take the tail angle at either a flat top section on the trans or the carb base. Need a little research there what aftermarket flathead serious. I know small block Chevys if the carb pad is level the tail is point down 3 deg on the rear axle I bet you could stick a magnetic angle finder across the U joint yoke with it orientated vertically. With out the joint in it obviously. that make since?
@trevorsworth, You may have missed the S#!t storms this question starts over the years. Are you going back to the OE cross spring, arms and axle, adapting the parallel rear springs and another axle? Do you have ride height fairly dialed in? This will make a big difference to how to attack it.
I'm going to keep what Sid did as much as possible which, today, means keeping the 3-spring setup. I see no problems with the parallel spring configuration as he had it. The rear that's in it probably isn't what he had in it when it was last on the track - although there's no way to know for sure. My interpretation of the information available to me is that this rear end came out of his '39 Dodge truck which may or may not have been a bit of a hot rod itself. That truck was wrecked in the early to mid 60s, as Guy remembers the night it happened. By this point the coupe was already up on blocks. My guess is at some point in the intervening years Sid started messing with it, maybe mocked up the Dodge rear to see if it would work to get the car moving again, and then got busy on something else and left it alone. No way he sent this car down the track with slicks and an open rear... that just doesn't make sense... especially given I have a photo of these slicks on the car, yet I had to buy & modify an adapter to get them to bolt to that diff. ANYWAY, I have two F1 banjos that will suit the car fine for street driving, but someone has cut the parallel spring perches off both, so I have to undo that. I have the option of using these "adjustable" bolt-on perches. These cost more and you are still supposed to weld them once you get them where you want them. I think that using those would let me bolt the wheels with the slicks to the diff, roll it under the car and get everything set up exactly as it would be sitting, tweak the pinion angle until it's right, and weld 'em in. But they aren't really made with the tapered tube in mind and they sure are expensive.
This is why I asked what the plan is. If it's the 48 open axle on the current parallel springs, get everything lined up and look up how to measure angles. Prepare to see grown men argue! BUT, if you are planning on blowing the bank on a QC, note the pinion is lower, so it would change things. EDIT: You posted while I typed this up. So open 48, leafs and you just need perches for a tapered housing. Check the hardcore rod shops, someone should be able to come up with something without a full on fab from scratch. Even then, it's box tubing with the right width, cut to work.
If the pinion angle gets wildly thrown off by a QC center down the line I'll know how to do it the second time. That's an expense for future Trevor to worry about. Today Trevor has this to work with.
If you have an iPhone, you should have the "Measure" app that has a really good digital level on there. Not sure if there is a similar app for Android, but I assume there is.
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