I need help choosing the right tire size for my car. This is a stock bodied 72 Chevelle (3800lb) +driver and is mostly street driven. I've been running an old pair of Goodyear 29x11s and it's obvious from the inconsistant 60ft times that they are giving up. Went to Carolina Dragway Sat. Made two passes on a set of borrowed 28x10.10.5 ET DRAGS before the rain came. These tires immediately produced the best 60ft and 1/8 mi. ETs (1.66-7.50) I'm thinking the improvement was due more to tire compound than the shorter diameter. Before I left I picked up a used set (18 passes) of MT 29x10.5x15s. Not sure that I need this tall tire, but for $100 I decided to try them. With 4.10 gears what do some of you think? And also, does anyone know the true height of these 29x10.5x15s? I know the "S" is for the stiff sidewall which I think I need for my heavy car, but I can't find anything on their website showing this tire. They go from 28 to 29.5 in their listing. Any advise would be appreciated. Cam (Crane 304) is supposed to work from 2500 to 6500 RPM. Converter is a tight 10" (2800). Thanks

Need more info like 60ft. times and mph. But I think it's the smaller tire producing a greater 60ft.time.

I think with the 4.10 gears the 28's would be about right. What is your trap RPM? That's what I would be looking at to get the right tire. You probably want to go through the traps around 6K. Unless your converter is really loose (not likely 10"@2800), you are probably closer to 5K with the 29.5's.

Troy.

Thanks, Only made two passes with the borrowed 28" tires and didn't check RPM at the lights, but with the 29" goodyears I was crossing at about 5600 and usually 112-113 MPH. 60ft times average low 1.70s with a best of 1.68 with 29s. 28s gave me a 1.66, but I still think it was just better rubber more so than the shorter tire. I want to be able to take advantage of these 29" MT just purchased, but they may be a little taller than I need. Just found out that there will be a rain date on Jan 5 (Carolina Dragway) so maybe I can learn something then. Thanks again

It looks like you have about 475 H.P. pushing a pretty heavy Chevelle. The shorter 28" x 10.5 "S" will most likely fit better and bite better than the taller 29.5" tire and it will allow the motor to RPM quicker. Be sure to put any of the above tires on a 10" wide, lightweight wheel. My son has run quite a few of the M/T Drags in several diameters and the 28" x 10.5Ws produced the best bite. These heavy cars definately need the "S" tire as they have stronger sidewalls to support the extra weight.

your gear should be about right for the 1/4 mile with the 28s and even the 29 inch tires but for the 1/8th you may need more gear to use your rpm ban .i cross the line in the 1/8th at about 6400 with 28s and 456 gears.the worn good years will take alot more heat to hook as any old slick will. newer slicks do make a difference.the mickeys need more air than the good years also and less burn out heat.heavy car stiffer side walls and more air pressure will make better 60 ft times.for a street car i woulnt go any higher on the gear.i run 14 pounds in my 28x10s in a 2880 pound nova with mickeys and 11 or 12 in the 28x9s good years.the mickeys out lasted the good year also but the last set i had were made in brazil .

The 60 ft went down because of the short tire. Basically with the tight converter, the shorter tire helped the motor rev faster to get the car moving. It's like going from a 4.10 gear to say a 4.33. If you got the 29's cheap enough run them and see what you cross at. If you feel you have the room to rev higher on the lights next time buy the 28's. I ran the hoosier 10X29's with 4.88's on my car crossing at 7200. Then went to a phoenix 10.5x29.5 which is a real big tire for a stock wheelwell and 60' 1.43 crossing at 7300 with another motor.

Man, I really appreciate and need all the help I can get. These 29x10.5x15s that I got at a deal don't exist. Got into a heated discussion with M/T yesterday and today. I had never seen a 29" tire listed in their catalog, but assumed it was a new deal. When I called tech ser to get the true height of the tire, he all but called me a liar. Said M/T had never offered 29s and I had to be mistaken, that he was sure it said 29.5. Told me to take digital pictures and proove it. I e-mailed pictures last night. After looking at photos of tire size and mold #, he told me it was actually a 29.5 and he guessed it was just stamped wrong. He agreed to sell me a set of 28x10.5x15s for 143.00 each. The 29.5s measure 29.9 and I agree with your comments, that just won't do for my application. Don't want any more gear. Harold, you said to put these tires on 10" wheels with my weight. Can you or anyone else out there tell me how much I will lose by putting them on my existing 8"? It's a money thing.$$ Thanks, everybody

If it's a money thing then run them on the 8's that you have. But optimally you should run a rim no more than 2" narrower than the tread. This will keep the tread of the tire flatter on the ground preventing it from from pulling up on the edges. I ran the 10x29's on an 8" wheel but I myself went to a 10" wheel for the 10.5's which were closer to 11" tread.

thats a hell of a deal on the tires if there new.the best deal i could find was 180 something on the last set of mickeys i bought.the 10s might be better but the 8s will work fine with what you have unless you are running the wides.i run 8s on my nova because thats all i can get under it and you see what my 60fts are. good luck anyways

im wondering if the cam isnt hurting you a little down low(if its a 304 dur.)
and the smaller tire is helping, making the rear seem lower-if the conv. is a tight 10", you might not be getting the flash you need-i never could remember to look @ the tach crossing the line, so i had to get one with a memory(then never could figure out how to use it-lol)

Thanks forced, Crane calls this cam a 304. The actual duration is 238/248 at
.050 off. It's probably still borderline, but staying with flat tappets, I thought it was my best choice. Edelbrock heads (oval) , RPM intake and 2465 pistons. Compression is around 10.4.Like I said, I'll listen to anything. My ETs suck compared to most of you guys.

Thanks forced, Crane calls this cam a 304. The actual duration is 238/248 at
.050 off. It's probably still borderline, but staying with flat tappets, I thought it was my best choice.

So is it 304 Adv?? Thats pretty mild ramps if it is. My FT is 300 ADV and 264 @.050.

I think the 28 helped the torque multiplication more then the traction. Two bad you didn't get in any more runs with them to see if tehy were consistent, that might have told you how warn the compound was.

Those Tech line guys always think they have the only correct answer possible. Prove them Wrong and it is a mistake! On both tires???:clonk:

Thanks Yellow68, Yes, the advertised dur. is 304/314 and lift is 544/567. On the tires, yes both sides of both tires were clearly marked 29.0/10.5/15s. He told they never made a tire that size so there was no way it could have been stamped that way. That was before I e-mailed the pictures. Then he decided to let me speak to his manager. I guess I can't complain. $143.00 ea. is a pretty good break. I'm taking everyone's advise and getting the 28s. Should have the tires Friday.