502ci Posted May 10, 2019 Share Posted May 10, 2019 Original post was deleted by accident so a new one is started. Repost your wheel and tire combo here so we can have the list again of what fits our cars. List wheel size with back spacing, tire size, any quarter panel trimming needed, spacers if used, airshocks if needed, spring spacers, wheel tub modifications, etc... Also add pictures so we can get see how they look. 😎 Example: 15x7"wheels with 4" of back spacing front. 15x8" wheels with 4 1/2" of back spacing rear. 255/60/15 front tires. 265/60/15 rear tires. 2 Quote Link to comment Share on other sites More sharing options...
stangeba Posted May 12, 2019 Share Posted May 12, 2019 (edited) Great idea! Got me wondering, how to set a data base like this up? Excel / Google Sheets? so people could search after it gets 100 entries. Bruce Year Front BS Front Wheel Front Tire Front Mods Rear BS Rear Tire Rear Mods 1970 4" 15" x 7" 255/60/15 None 4.5" 265/60/15 None I don't know if this link will work?? https://docs.google.com/spreadsheets/d/1i07rkMPKa6FNuPD_X5J62h0cI_Y-tQpBBlXWFRR1P7Q/edit?usp=sharing Edited May 12, 2019 by stangeba added link Quote Link to comment Share on other sites More sharing options...
stangeba Posted May 12, 2019 Share Posted May 12, 2019 If you like, I can add all STOCK data for the three years but I don't have that information. Bruce Quote Link to comment Share on other sites More sharing options...
MCfan Posted May 13, 2019 Share Posted May 13, 2019 1970 Monte Carlo Front: 15x7" rally wheel; 4.5' back space; 255x60-15 BFG (1" spacer in front coil prevents rubbing) Rear: 15x8" rally wheel; 5" back space; 275x60-15 BFG (3/4" sidewall clearance with fender well - no trimming or rubbing) 1 Quote Link to comment Share on other sites More sharing options...
MCfan Posted May 13, 2019 Share Posted May 13, 2019 1970 Monte Carlo SS454 Front: Stock15x7" rally wheel; 245x60-15 BFG Rear: Stock 15X7" rally wheel; 245x60-15 BFG Quote Link to comment Share on other sites More sharing options...
stangeba Posted May 13, 2019 Share Posted May 13, 2019 Some great pictures everyone! I modified the sheet and added the new info 5/13/2019. Bruce https://docs.google.com/spreadsheets/d/1i07rkMPKa6FNuPD_X5J62h0cI_Y-tQpBBlXWFRR1P7Q/edit?usp=sharing Quote Link to comment Share on other sites More sharing options...
stangeba Posted May 13, 2019 Share Posted May 13, 2019 1986, My 71 stock rally wheels fresh from painting and new (now replaced) GR70x15 UNI-ROYAL SWS tires. Bruce Quote Link to comment Share on other sites More sharing options...
snomobeelr Posted May 29, 2019 Share Posted May 29, 2019 Wheels are a tricky thing. ........................................................................................ The rally's with 4 inch backspace were outward The American Legend 4.5 backspace were inward ......................................................................................... Wheels & Tires ................................................................ 15 X 8 4 Inch Backspace Corvette Rally wheels. (All 4 Wheels) 245-60-15 (All 4 Wheels) BF-Goodrich ***************************************************************** 17 x 8 4.5 Inch Backspace American Legend Racer (All 4 Wheels) (Custom Powder coated) Fronts 245/45/17 BF-Goodrich Backs 255/45/17 BF-Goodrich Quote Link to comment Share on other sites More sharing options...
Helen Posted August 19, 2019 Share Posted August 19, 2019 Hi all! I am looking to replace my current 245/60 R 15‘s. I am thinking about going stock with 215/70 R 15. 70 is also pretty high; is there a shorter tire I can go with? How much handling will I be giving up? I live amongst curvy roads. Thank you. Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted August 19, 2019 Share Posted August 19, 2019 Hello again Helen. Depends on how you drive on those curvy roads. The skinnier tire will adversely affect the road manners of your Monte. Do you have the 245's on all 4 tires? In the new members section I believe you said it's a 350 car. Since you are on curvy roads alot I suggest bigger sway bar in the front and boxed lower rear control arms with a rear sway bar. Even the factory F41 arms and sway bars would make a huge difference in the way your Monte would feel. Hope this helps. Quote Link to comment Share on other sites More sharing options...
Helen Posted August 19, 2019 Share Posted August 19, 2019 Thank you. I am stuck somewhere between keeping a nicer handling package, or going more stock. See previous response. Quote Link to comment Share on other sites More sharing options...
DragCat Posted August 19, 2019 Share Posted August 19, 2019 Hi Helen, welcome to the insanity 😁 You have just ventured into the keep it stock or upgrade for whatever reason cloud 😯 I can't speak for your winter conditions, but on your roads i'd want more rubber on the ground. Unless your at Pebble Beach I doubt anyone will question your going to a 60 series, I'm running 225-60R-15's. The original stock G70-15's had a tread width of 6.70 and a section width of 8.50. In contrast my 225's have a TW of 7.5 and a SW of 9. Didn't want to go all tech on ya just some data to ponder. There are lots of handling upgrades but ya have to have some good sneakers on our heavy Monte's. Quote Link to comment Share on other sites More sharing options...
DragCat Posted August 19, 2019 Share Posted August 19, 2019 On 5/12/2019 at 9:44 AM, stangeba said: If you like, I can add all STOCK data for the three years but I don't have that information. Bruce Bruce, according to my sales paperwork the 70 came with either G78-15 or G70-15 tires . Quote Link to comment Share on other sites More sharing options...
714024SPEED Posted August 19, 2019 Share Posted August 19, 2019 I have 215-70r15 redline radials on my 72 car has all factory springs and tires fit fine. The shorter the tire the more of the "road"you will feel. 1 Quote Link to comment Share on other sites More sharing options...
milehigh72 Posted May 5, 2020 Share Posted May 5, 2020 does anyone run 18 or larger wheels? Quote Link to comment Share on other sites More sharing options...
tttm2 Posted June 5, 2020 Share Posted June 5, 2020 Rears: 17x 8”, 4.5” backspace tires: Mickey Thompson 275/40/R17 ET street R’s Fronts: 17x 8”, 4.5” bs tires: Mickey Thompson 245/45/R17 ET street R’s 1 Quote Link to comment Share on other sites More sharing options...
Canuck Posted June 14, 2020 Share Posted June 14, 2020 255/60/15 tires on 15x7 rallys. No rubbing or issues whatsoever. 1 Quote Link to comment Share on other sites More sharing options...
Canuck Posted June 14, 2020 Share Posted June 14, 2020 245/60/15 tires on 15x8 rallys with 4 inch backspacing. I had a slight rub on the rear and had to bend the quarter panel lip a little for clearance on one side. 1 Quote Link to comment Share on other sites More sharing options...
RODS70BB Posted August 8, 2020 Share Posted August 8, 2020 Rear - 17x 8.5 5.75” backspace Toyo 275/40/R17 Front - 17 x 8.5. 5.75” backspace Toyo 235/45/17 I’ll post pictures when wheels come back from powder coated. Quote Link to comment Share on other sites More sharing options...
jim's 70 Posted November 30, 2020 Share Posted November 30, 2020 Anyone run an 18x9.5 5.250 backspace on the rear. ? Lips are already trimmed.... just figuring if they would fit and what size tire Quote Link to comment Share on other sites More sharing options...
MCfan Posted December 1, 2020 Share Posted December 1, 2020 Quarter panel clearance is the obvious consideration. Maybe some member here will have experience with that exact wheel and can get you in the ball park, but I can give you a comparison to my known rear tire/wheel combo using tiresize.com. I have 275/60-15s mounted on 15x8 rims with 5.5" backspace (+25 mm offset) with right at .6" clearance between the sidewall and untrimmed wheel well lip. A 275/45-18 is the same width and only .3" shorter, BUT when it is mounted on a 18x9.5 rim with only 5.25" backspace (which is zero offset) the tire comparison and wheel offset calculator say the sidewall will be .98" further outboard than my current setup. Clearly, that tire/rim combo would NOT work with my untrimmed wheel well opening because I only have .6" clearance. Maybe that combo will work with your trimmed wheel well opening but I am certain a 18x9.5 with greater backspace (positive offset) would be a better/safer fit. There is lots of room inboard for wider tires and rims on the rear of our first gen Montes, but very little extra room outboard. That means to get fat tires on wider rims to fit safely we need to move the combo inboard by using rims with positive offset - the wider the combo, the more offset is required. Every 6mm of positive offset increase the backspace dimension by 1/4". 3 Quote Link to comment Share on other sites More sharing options...
jim's 70 Posted December 1, 2020 Share Posted December 1, 2020 Thanks for the infoDennis. The wheels I’m looking at don’t offer custom offsets, just what they produce.... I’ll have to keep shopping Quote Link to comment Share on other sites More sharing options...
jim's 70 Posted March 16, 2021 Share Posted March 16, 2021 Just to add the info here 18x9.5 5.25 backspace 275/45r18 Mickey Thompson drag radials lil fender trim and they tuck right in, and my car seems to sit lower then the rest even with cargo coils fronts coming soon Quote Link to comment Share on other sites More sharing options...
Bad Wolf racing Posted February 16, 2022 Share Posted February 16, 2022 I have a similar question. Here's where I am; QA1 stage 2 pro touring suspension and building it for the Optima Ultimate Street Car challenge plus cruising, shows, etc. QA1 suspension is in the middle of it's range on the three position coil overs. The 225/70R15 BFGs on there now rub very slightly if more than one person is in the car on a very tight turn like when backing up or turning into a parking space. Has anyone had any luck with an 18 inch wheel with enough offset to maybe tuck it back a little more and if so how wide were they able to go? I'm trying to fit as much rubber under him as I can for track performance. For cruising / shows I'll probably keep the stock rally wheels and 225/70R15. I'd like to get to 275 or wider with a low profile sidewall for the track (not to mention extremely high speed rating. I'm a little embarrassed for asking this as I was a BFG performance specialist back in the late 80s / early 90s but technology has changed a lot and we never had the wheel sizes or tire sizes we do now; a 245/60R15 was about as big as you could go back then. Quote Link to comment Share on other sites More sharing options...
MCfan Posted February 16, 2022 Share Posted February 16, 2022 Robert, where are your 225/70R15s rubbing on tight turns - outside or inside tread? On the frame or inner fender? If they are mounted on stock 15x7 Monte rally rims, their offset is .30" (+8 mm). I doubt you would have any rubbing anywhere with 225/70s on stock Monte rallys with stock suspension so maybe the rubbing is entirely due to lowering with the QA1 coil overs? Regarding wider tires on the front, if you stayed with a "stock" +8mm offset on any width of 18" rim, your current inside and outside clearances with 245/45, 255/45 and 275/45 width tires would both be reduced by .35", .55" and .95" respectively. Depending on where your 225/70s are currently rubbing, you could shift a wider tire outboard a bit with LESS offset (+6, 0 , -6mm) or inboard a bit with MORE offset (i.e. +12, +18 , etc.). Someone may have been able to successfully run 275s on the front but I have not heard of it. I am running 27" tall 255/60-15s in front on non-stock 15x7 rallys with +12 mm offset (4.5" backspace) using a 1" spacer in stock AO front coils. I can still get a slight rub on the frame on hard turns if the front end is also depressed like backing out of a dipped driveway entrance. After running many, many wheel/tire combos through the tiresize.com wheel offset calculator and comparing them to known (measured not guessed) clearances of real life wheel/tire combos using stock suspensions, it is apparent to me that the optimum offsets for any width of rim are +6mm (1/4") on the front and +12mm (1/2") on the rear. Both of these offsets will keep a wider tire/wheel combo almost exactly centered within the available stock wheel well space. Note that the factory offset of .3" (+8mm) is a compromise between those two optimums since they could only use one rim for both front and rear. The wild card in your case is the non-stock suspension and I suspect that even a minor lowering of your front suspension may be causing the slight rubbing with the 27.4" tall 225/70s. Going to a 245/45 or 255/45 tire on an 18" rim will increase your top clearance by .35" and .20", respectively but the inside and outside clearances would also be reduced as mentioned above. A 275/45 is even taller than your current 225/70s so I can't see that working in any case (width or height). Hopefully, some member with practical experience in stuffing fat tires under the front of their Monte will chime in with how it can be done with suspension or body mods or whatever. 1 Quote Link to comment Share on other sites More sharing options...
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