Interesting I presume you are gearing up(bigger Dia )I would have thought that you would have been better of with bigger side wall on the 18s . I am looking to get rear wheels and tires for the magnum to have a go on the strip I was thinking 18s with mts or hoisiers but not even sure if 18s will fit ?Anyway I would be keen to know how you get on with the kuhmo’s
I’ll let you know and will hopefully have someone there taking footage so hopefully will get a good number of passes in.
If traction on the street is anything to go by it should be good. When running 18’s or 17’s your somewhat limited for tyre choices that will fit under a vf especially if its lowered.
If your in Qld you could borrow my hoosiers on the 18’s but they’re only 245/40r18’s. Even still they never lost traction and I would have done easy 50 passes on them and they’ve still got at least another 20-30 left in them. They’re the dr2 compound so they’re harder than the MT and M&H dot radials. They dont smoke up much at all when warming up until 3rd gear when they start, but they last heaps longer and stick so imo they’re the best value dot radial....yet not strictly legal for road use in Australia..
When I changed the diff ratio to 3.9 with the 18 inch hoosiers I calculated the final drive at 4.1 due to the rolling diameter and it was nosing over big time down the drag strip so currently with 275/35r20’s the final drive will be about 3.68:1 which I reckon will be in the perfect range for the cam and the converter.
PS I love hq’s I owned two geniune gts coupes in my time. My first car when I was 17 years old which had a sbc I paid $3500 and brought the last one as a roller with a 9 inch housing for $1500 then restored it and sold it for 12k about 18 years ago. Wish I still had it but couldn’t afford one these days. My bro had a hq statesman which I wouldn’t mine either.