I'm looking at tires for the rear of my 70 cuda 426 hemi approx. 600 hp 4-speed 4:10 strange s-track calvert split mono 9 way shock cal-tracks and QA-1 double adj. front. 3800#s without driver

Current nitto 275/60/15 worthless even at track.

It looks like the only tires that will fit are MT. ET. SS 275/60/15 or MT. ET. 28X11.5R15 bias #3554 or QTP 17601.

97% street driven is it worth the rough driving of a bias ply for traction over a better riding and poorer grip radial?

I would suggest the bias ply tire. I couldn't get a set of M/T 325R50-15 radials to hook either. Put on a set of 28x13.5x15 M/T ET streets and went 10.90s from dismal 12.00s at 129mph, no other changes. Radials don't seem to recover from the violent hit a clutch car has. You might get the radials to work with an adjustable clutch but I think your tuning window will be very narrow and wear will be high. My 2 cents...

Seems to be the normal thing with a stick car.. just cant
take the shock on the hit.. thats why the bias work better..
on the street you might want the radials

I run the same M/T ET streets on my Savoy and I'm kinda glad I get some spin at the hit. You really don't want a dead hook with a car that heavy
Gus

I have a set of MT. ET. SS 275/60/15's purchased this spring with one track outing on them I'll part with cheap. PM me if you're interested.

You probably need different shock/air pressure settings for strip than street. Be careful how much bite you give the tires. I was breaking transmissions at 3,100 pounds and less than 600 hp with a 30 lb. flywheel, 5,000 rpm launch with too loose a shock setting. Ask Chip (an8sec70cuda) about his tire combo. He mentioned something once about mixing bias ply and radials giving him problems at the track. But I would probably go for a dedicated set of bias slicks for racing.

Thanks for the input I bought the MT bias ply et streets today

Good choice. The radials won't work well w/ the 4 speed.

No problems at the track w/ any mix of tires I've ever had. My only complaint is w/ bias ply FRONT tires on the street...they follow ruts like train tracks. Doesn't matter what's on the back.

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I agree Chip I run the same 28" sportsman on the front you do and they follow every grove.

Now I need to decide tubes or not? 4 speed need soft sideways and adding tubes stiffen sidewalls?

All this thinking is giving me a headache. Lol

At your weight, I think the tubes would be good. Not to mention they keep the tires from leaking down. I used to run 28x12.5 ET Streets years ago and they'd lose a few lbs. overnight w/o tubes.

I only weigh #150.

OK, so one tube will easily keep you afloat in the pool. But for your car, I think 2 would be better.

You've always been good at spending my money. Lol I bought a new set of Billet Street lites to go with them..and of course polished no black!!

It gets better...if you run tubes, you have to either screw the tires to the rim or use beadlocks.