Help, 2nd request, 74 Big Block coupe....

One more try,

I am buying new tires for my 1974 454 4 sp coupe and would like some opinions,

I am looking at the T/A's 235/60/15, any other suggestions?

Thanks.

Jasen

Reply to
J Nyrose
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I remember running G60 TAs on a 71 454 back then, but I don't know how that translates to today's sizes. I recall that G 60 could cause a rubbing problem on the front with some tires. Believe the car originally came with

70 series nylon tires.

Reply to
tww1491

They will rub, so will 225/70X15 but that is what is recommended by Tirerack, it also looks to big in the wheel well. Actual size used was GR70X15 and is comparable to the 215 series today. I have Goodyear

225/70X15 and they do rub in turns that work the suspension up and down, width is the problem, not diameter.
Reply to
Dad

I am currently running 235/60's with no rubbing, I guess I will stick with that size.

Thanks

Reply to
J Nyrose

Which brings up a question of the steering arm on the '74 spindles, do they still have 2 holes? If so which hole is the radius/tie rod in, forward or back? Also my guess is you have power steering, correct?

Reply to
Dad

The original was a GR70-15. The Alpha sizes are no more, as they did not always translate into the same size by manufacturers. The Metric sizes are not always the same, either, but they are closer to being the same.

Basically, equivalent tires are:

F70-15 215/70-15 F60-15 235/60-15

G70-15 225/70-15 G60-15 245/60-15

H70-15 235/70-15 H60-15 255/60-15

L70-15 255/70-15 L60-15 275/60-15

The 235/60-15 actually looks a bit small in the flared '73 to '77 fenders and many run the 255/60-15. The 235/60 looks better in the '68-'72.

The 235/60 can have minor rubbing on the front at full lock on the frame at the steering box bolts and the idler arm bolts, so it is important to always have the rounded carriage head bolt in here. Never replace with a regular bolt and especially never have the threaded end to the outside.

The 255/60 can have the same rubbing, plus the back edge of the wheelwell and the top of the inner lip. These were trimmed at the factory for the '78 and up with the 255/60-15 option.

The 255/60 can also rub on the emergency brake cable bracket on the trailing arms on the rear, but the clearance can usually be gained with minor work (some grinding, maybe move the bracket if excessive). Be sure to fit a tire to the wheel and check before driving out of the store with them on the car.

The 245/60 (the G60 equivalent) is a better fit from looks than the 235/60 and it less a problem from rubbing than the 255/60. However, they are usually hard to find.

Fitment is based on using factory rally wheels or factory aluminum wheels at stock ride height. With age and mileage, the ride height can vary. The factory aluminum actually give a better fit of the 255/60 on the rear than the rally wheels, so you may not have any issues on rear. You will still have them on front.

Reply to
Tom in Missouri

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