Flanders

I've got 275's in the rear of mine. No rolling required, no rubbing. Still need to lower the front-end a bit, but lots of room. front: 17 x 8 with 4.75 bs back: 17 x 9.5 with 5.7 bs front: 245/45/17 back: 275/40/17

the qa1's are definitely working -- on the softest setting i can push/pull the shaft (when they are out of the car) relatively easily. On firmest setting, it's a lot harder.

reviving this thread again. I've loosened off the shackles completely, and the car is still super-stiff when I try and bounce the rear end. I have QA1 adjustable shocks on softest setting. Shackle is at the 5 o'clock position (maybe 4:30) which seems to be ok. I don't think it's binding. I think the scott drake mid-eye 4.5 leaf springs are just stiff. And having the rear end so much stiffer than the front really makes the car oscillate funny on the highway. I may try Eaton's stock-spring-rate leaf springs that lower the car by an inch. ML1567-1. Any other opinions?

yeah good thought -- I'll re-check. I put them in a few years ago, thought they were tightened while car on the ground.

reviving this thread.... I've been playing around with the dampening on my QA1's, and I'm pretty sure it's my leaf springs that are causing my stiff-ness. When I push down on the rear fender, the car barely moves (and if I really give it a jolt, it bounces a bit....which explains the odd oscillating/bouncing I see on some hwy stretches). I have some scott drake 4.5 leaf mid-eye leafs in the back. They are not very old, but I'm getting the sense they're not very spring-y. I like the height of the mid-eyes, but I really want a smoother ride. What do you guys run in the back that isn't super firm?

...I've got them set on "6" out of 18. Although I might actually firm them up a bit -- I get a wierd oscillating on a few parts of the highway (where the rear end of the car actually feels like it's bouncing!) probably due to front being a lot firmer than the rear now....

Just wrapping this up -- I put QA1 single-adjustables in the rear, and it's definitely softened it up a bit. Still firm, but not jolting anymore over the bumps!

thanks for the tips. I'll take a look at bilstens -- I was even looking at the QA1 rears, just need to see how fancy I want to get for a street car.

I took my car out for a good shakedown run (finally) and noticed that the rear suspension seems quite hard. When I hit some cracks/bumps in the road, it's a hard THUMP from the back-end. There's barely any dampening going on from the shocks. I have mid-eye leaf springs (a few years old) and some KYB shocks (7 years old, minimal mileage). Any suggestions on how to soften it up so it doesn't feel and sound like the back end of the car is going to split open on the bumps?

Worked like a charm. I measured twice and cut 4 times (doh) but this finally did the trick. I was able to move the trans over by 1/4" (maybe even just 3/16") and it got rid of my rubbing. My crappy old rubber mount may need replacing soon anyway (it's old.) but it's an easy thing to modify again if required. Driveshaft goes in next, so fingers crossed all my trans/driveshaft/pinion angles are good.

The position of the shifter itself is already fantastic with the TKX. It's already 'back' and has configurable position for the shifter arm position. I just need one that's narrower where the rubber boot is. TKX shifter location (purchased 'kit' for '69 Mustang from American Powertrain)

another detail -- This is with the stock rubber transmission mount. It's a bit thinner than the American Powertrain one. I think I'm going to hog out my rubber trans mount holes, rather than drill out the MDL crossmember holes. I'd rather drill through a $30 part than a $165 part :) Paul at MDL sent me this too -- a shifter that has a flat right-hand side, to account for my fitment. More things to consider, but I think I'll start with drilling a few holes in the stock rubber mount. That one is free. https://www.moderndriveline.com/shop/shifter-accessories/mdl-shifters/shifters-tkx/ford-shifters-tkx/mustang-65-66/65-73-mustang-tkx-quick-stick-shifter-1-back-offset/

The folks (Paul) at MDL have been fantastically patient with me :D but there is definitely not supposed to be much room between the top of the trans and trans tunnel with the TKX. This is indeed the proper mount for the TKX. After a few hours of adjustments, I managed to get the MDL mount aligned and installed. The below pic shows my clearance issues with the shifter boot/mechanism, so I need to fix this. Not sure if my car is slightly crooked (?) but it definitely doesn't quite align perfectly. There is zero wiggle room with the MDL crossmember mount. Current options: -somehow get in there with a dremel and make room in the floor for the shifter position. -hog out the modern driveline mount bolt holes (where base of trans mounts) so I can shift trans over by 1/4-1/2". I'm open to opinions :) I'm still amazed at the height diff between the American Powertrain mount and the MDL one, so consider this thread a huge HEADS UP to anyone doing this.

Well, I'm stuck. I've pinged Modern Driveline to see if they can help too. Posting more pics here for prosperity. The factory trans mount/bushing is a bit thinner than the American Powertrain one, but not enough to make the ModernDriveline crossmember line up with the bolt holes. I still can't believe how different in mounting height the American Powertrain crossmember is compared to Modern Driveline. I can't even raise 'up' my transmission much more to work with the MDL one, since it will hit the trans tunnel support. Right now I've hacked up my American Powertrain one to make it work with my exhaust, but need to take it to a welder to re-inforce it. That's my best bet at the moment.

more pics, Modern Driveline mount compared to stock (basically the same). This is the "low profile" one, I don't see a 'regular' TKX one on their site: https://www.moderndriveline.com/shop/cross-members-mounts/ford-crossmembers/mustang/1967-73-mustang-cougar-low-profile-crossmember-tkx/ Also a pic of the transmission held by a jack where the American Powertrain mount held it up, showing how much difference there is in height with the bolt holes. I'm wondering if I need to use the factory rubber trans mount, which is a bit skinner than the one from American Powertrain. Stay tuned.... also still need to make sure this is going to clear my exhaust, otherwise I'm back to butchering up the american powertrain one.

The plot thickens. I've thrown money at this problem, and purchased the Modern Driveline TKX crossmember mount. Unfortunately, it's a skitch different. The height of the plate to the frame mounting holes is different. I haven't gotten under the car yet, but I can instantly tell a) the MDL one is far better quality, but b) it's going to raise my transmission up by > 1", which might actually squish the shifter boot on the top of the tunnel. I will report back once I've gotten under the car -- maybe I need to swap out the rubber mount on the base of the transmission. For comparison, the MDL mount is the shorter one. The American Powertrain one is the taller one (which I've grinded to heck, so it works with my exhaust --needs some reinforcements welded to it, should I choose to go this route)

Just to follow up, I've sorted out my clearance issues. I had moved my engine forward about 1/2" so that my (new) TKX transmission mount would line up properly. If I put the engine back to where it was (smack head!) then things line up perfectly. I do need a new z-bar as mine is bent and reinforced (way before I owned this car), which also helps with the clearance. I need to butcher up my tkx crossmember, but I can deal with that much easier.

heh. That cable kit is interesting. Requires a lot more work than I'm willing to do at the moment with my stock bellhousing :D however maybe I'll change my mind. Lol where was this about a month ago before I put everything together and in the car!

Perhaps another question: Is the z-bar easy to modify? If I take this to a welder to cut up, are there any things I need to consider?

Naturally, during final assembly I discover that parts don't quite fit with each other. My TCP steering looks nice, however the stock z-bar now interferes with the steering shaft. The top curved arm of the z-bar hits it. Is there a replacement z-bar that has the top arm mounted closer to the boss on the engine?

that above pic looks custom :D I've just attached the mount, and have a few notes for anyone else doing this. I used this: I had to clearance the corner of the mount a bit, above the elongated hole (left, in the pic). Otherwise the bracket was hitting the old cross-member mounting point, preventing the bolt hole from lining up. It does indeed go on the 'rear' side of the original crossmember mount. Also found that this bracket is not compatible with the JBA H-pipe (for 351W, manual trans). The right-hand side, lower corner of the mount (in above pic) hits the exhaust. ...so now I need exhaust work done again. Or, I find another transmission mount that fits (the stock one won't work).

I've got a TKX 5-speed going in, but have a few questions about the crossmember mount that came with the kit. It's their "x-factor" mount. It's quite a different shape than the factory mount, and instructions (should I choose to read them) are pretty vague. I'm curious if the attachment points on the frame are on the front-side, or back-side of the original crossmember mounting position. Original mount, for reference: Was hoping someone can shed a bit of light, otherwise I'll just arse around with it and see what fits best once I have the engine+trans hanging in the right position.

hey yeah thanks for the suggestion. It has had oil in it, but removing the reservoir and adding a bulkhead-style connector is an option I'm toying with. I'd need to see how much of a pain in the ass this is!

yeah, I don't know about the longevity of that. I'm going to get a 6-AN to barb fitting. Then I'll just use a little rubber hose (with clamps) between the pump outlet and the barb on this fitting. It's low pressure, and down low in the engine compartment so hopefully won't be seen!

Thanks for the tip! that covers the high-pressure side. Any idea on how to connect the low-pressure "barb fitting" on the pump to a braided stainless line?