So here we go,,, I'll post this in several posts so please save the replies till its finished. I'm also trying a batch resizer, so I'm not sure about the size of the pictures. I started by making a template of all the holes in the m/c, including the center of the brake pedal pivot. Drill a small hole at the center, so it was visable from both sides. The m/c will be a little lower than the stock one, so the pedal pivot has to be lowered 1/2. I used a chunk of 2x3 box, 3/16 plate would have been better. I had to flip the template over and work from the backside. Leave it long on the front side so you can add another bolt hole in the front. Transfer the marks to the back of the mount. Cut all the holes, drill a small hole to mark the pivot center. (This is when I cut the front off the box to make it a channel.) Weld a piece of heavy wall tubing on the inside of the mount, centered on the little hole. The shaft is 3/4" so 1" .120 wall is what is needed. (Should have used bronze bushings and larger tube, but this is what I had.) Spilt the upper lip of the box and fold it down onto the pivot. (I braced the hell out of this thing.) Don't worry about folding the front over, I ended up cutting it off. (explain it later) For the actual m/c mount I used 1/4" flat strap, drill to fit the new piece.
Bolt the strap to the m/c and hold it in the hole. Make sure that the clamp for the lid is clear of the pivot shaft!!! In order to get it clear I had to trim a 1/4" off the front of the crossmember. It has a 3/4" pinch weld so no strength is lost. I also had to clearence the clamp boss on the dual pot. Bolt the mount in, and hold the m/c in place to mark the location of the m/c tab in relation to the pivot mount. Cut the bottom lip at the mark and remove the lip on the pivot side. In order for the pot to fit the bottom lip needs to be cut down to 3/4". I curved the end and rolled it up around the m/c flange and welded it down. (I braced as much as possible, it is the brakes after all.) I added another brace between the pivot and the top of the m/c tab and welded everything all the way around. The front bolt boss has to be angled to match the frame. (Chunk I cut off) I put a couple gussets on it as well. Now you should have something like this! If you have an autospastic trans, your damn near done. Round the corners and bolt it in!
Now the fun part!!! Clutch parts. Bolt the mount in but leave off the brake pot, slide the clutch pedal shaft and tube back in. Hook up the pedal to get the tube centered. It needs to be welded to the top strap on the pivot mount. I added a short piece out from the strap and cut it off at 2 1/4" out. (Thickness of the old m/c.) Now you can measure down from it to the top of the clutch tube. Cut the stock tab off where it will meet the added piece and weld it up. Both the clutch shaft and the drop arm will now hit the m/c mount, so,, the clutch shaft has to be rotated to the top. Add a piece of 1/4" above the pedal side of the arm and cut a hole in it to receive the shaft. Add another piece of strap to the front side of the arm and cut the corner off. Now back to the clutch shaft. The shaft cannot just be rotated 180 because the arm will have to run foward, not down in the relaxed position. Cut the tab off and re-assemble the clutch. Hook up the pedal and let it rest on the floor and allow the drop arm to relax. (Make sure it will clear the m/c bolts.) Mark the position of the slot on the clutch shaft and weld the tab back on. When you pull the pedal up to its normal position the arm should rotate forward. When its depressed the drop arm won't hit anything.
Almost finished!!! The brake pushrod needs to be a little longer than the stock one. It needs the retainer from the new m/c and the adjuster from the old one. I cut the old one off at the tip and welded the new tip on. Mine needed to be 1/4" longer but yours will probably be different. The pushrod will need to be shimmed over to meet the new m/c center. This one needed 1/4", which just so happens to be the thickness of a jam nut, which will fit inside the loop of the new pushrod. I cut it off, drilled a hole in it and used it to hold the return spring. The clutch linkage from the drop arm to the bell housing will need to be shortened mine was 1 1/2". I added a nose support under the crossmember to keep the nose of the pot from trying to move around. I drilled and tapped the bottom of the brake pedal pivot for the grease zirk. (No pic, sorry) Thats all folks!!!! Think I covered everything. Questions??
Thanks,,, I should add that before you install the brake pedal you should drill the new front hole. I used 3/8" bolts, run a tap thru the factory holes and I drilled the front frame hole to 9/16" and flush welded a nut in it. Most of this stuff welds real nice, the frame especially, but the drop arm doesn't weld very well at all. Get it hot and keep it there, at least thats what worked for me.
Well, gang.....hang on to your shorts!!! Da Tinman goes WAY beyond being a master fabricator! The amazing thing about him and his work is that he's willing to share his knowledge and experience with all of us without hesitation. He's the key person on our fuel altered/nostalgia funny car team. Stay tuned on this one, folks.....it'll be a hell of a ride!!
OK, all I can say is "you had ta be there!" I be Tinman's Dad, and was there for various parts of this fabrifornication- where his creativity comes from, I don't know. It sure skipped a generation with me... He's been working on a "show car" (tinwork is outstanding as is normal for him), and said this was a welcome break to work on this rolling rust bucket. It goes- well, kinda- and now it will stop. Exhaust system is next, rattle can primer 'til we can get the body squared away, and we can drive it while we work on it. His idea of a break amd mine are way different... And, Ron, yer right, this'll be one hell of a ride!!
Forgot I had this booked marked. thanks for resurrecting it. I also wondered the same question as shoebox1950.
Wow benna while have to dust off some cobwebs.... 72 I think. They should all be the same until they went to disc drum. Thanks for popping this one back up!
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