Mark Maras

"It sounds like the drive shaft is gonna come up through the floor" is no exaggeration if the nose of the diff. is lifting and falling. With the help of a friend inside the car, position yourself so you can see the front of the diff. A mirror may help. Pull the parking brake on, start the engine, put the trans in first gear, and SLOWLY release and slip the clutch. Look at the diff. nose to see how much vertical movement there is.

I agree. In the beginning, this problem looked to me like it was a distributor cap, rotor, wire, or spark plug because it was only fouling one plug. It was either that or an internal problem. Countless plugs, new wires, cap, and rotor haven't made much difference but just to put my mind at ease, swap a plug wire with #4 and see what happens. Be sure all the wire connections are on all the way and secure. My son's Subaru had a plug wire that kept backing off the plug. He cured it by lubing the inside of the boot with dielectric grease. The boot slid all the way on the plug with grease.

Out of principle. The improvements? may have started with the automatic choke or possibly starter solenoids. Caveat, I drove a 39 Chev pickup for a few years.

I don't foresee any major problems. I'd also want to strip the vehicle of all the extraneous B.S. they've added to newer cars in the name of improvement.

I don't remember any access to the trim screws from the front. It was always a PITA to dig the mud out of the screw heads in the headlight bucket but I always had to go in from the backside.

Refresh my memory. What were the compression readings the last time you did a compression test? Was #4 lower than the others?

I've removed the cable only from the transmission end. There was a frayed wire in the center of the cable. You'll have to turn the cable while pushing on it to get it to line up with the speedometer connection.

Possibly but it could also be a frayed cable that catches on the inside of the sheath when it flexes. I'd remove the sheath and inner cable from the car. pull the cable, clean everything, lube, and reassemble if there's no damage.

My 71 speedo was always steady. I'd check the speedo cable and sheath for defects. The flexing of the sheath when going over bumps may be related.

Brain fade. I've spent the last week working on my brother's 31 Model A Hot Rod with a 350 Chevy in it.

How long does it idle before fouling a plug? Assuming (correct me if I'm wrong) it starts to run on seven cylinders, will the plug clean up if you run the engine at high revs (Italian tune-up) for a while?

I don't know where the oil is coming from but like C.O. I don't think it's coming from the carb reservoir. Ztherapy has an excellent video on SU carbs. It describes their function in detail and has many tests to ensure the carbs are working properly. With that thought in mind, you might give Steve at Ztherapy a call and ask him about the oil problem.

The studs in the pics don't look like they're parallel with each other nor does one of the studs look like it's installed 90 degrees to the hub. I agree with Charles, put a nut on the offending studs and tap them.

With the engine off, lift both carb pistons to the top. There should be considerable resistance in both. Then let them drop. They should drop at close to the same speed and hit the carb bridge with an audible clunk.

How often do you have to add oil to the carbs?