i’ve done a bunch of searching, but have not found a definitive answer. Does anyone know if the Gr4 wheels will fit on a factory 74’ GTS? I currently have the old Hall ultras on and have the origional Campys.
I have been considering putting the old Campys on but love the wider look. To me the Mavics gives the best of both. An old school factory correct look (at least on the Gr4 cars), with the width that fills out the fenders.
Picture for attention.
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The Group IV wheels are 10" front and either 13" or 14" rear depending on which rear rim you have (they made both). There is only one street legal tire available for this rim combo which is the Pirelli P7s which will cost you about $2800. for a set. I have 10 and 13" wide Gotti's on my car and they are under fiberglass Group IV flares (riveted on per the way the factory did). There is no way those rims would fit under a GTS flare. You also have to cut the sheetmetal as the tires stick out very far and will hit in the corners when turning the wheels. The Marvic rims are period correct in magnesium but you will have to cash in your 401K for a set. A much cheaper alternative is to buy a set of cast Roin Group IV rims which they make to spec from the original wheels. But again, you will have a wheel tire combo sticking out 4 " on the back and 3" in front. Kinda like a Dukes of Hazard thing. Hope it helps.
Appreciate the response but still a bit confused. I currently have 335s in the rears that seem to fit no problem. My understanding is the 14” x 15” would be a 345 which is 10mm (.4 inch) wider. Also, it looks like Mavic have custom offsets. So not sure how the rears would look 4” too wide in the rear given they are 1” wider than the current set up shown here?
You are correct wrt the tire size - 345/35-15. It's the offset of the rim. Mine are a 5.0" backspace which is pretty close to the Group IV factory rims. Not sure what your wheels are but they must have a deeper backspacing to tuck under a narrower body car. Try taking one of your rims off and position it with regard to the hub with a 5" backspace. Maybe its not 4" with your GTS flare but it will still be beyond the edge IMHO.
Drop a level from the edge of the flare and measure back to the hub flange. Marvic only make the 14" width rear (not the GT5 / GT5S 13") and they sit out to the edge of a GT5 / GT5S flare.
Marvic have technical documentation on their site with offsets.
Group 4 https://www.marvic.it/public/p...0-14x15_2016-eng.pdf
GTS 10" https://www.marvic.it/public/p...TS_8-10_x_15-eng.pdf
This thread may be of help, with photos of Marvic's 10" GTS rear wheel. https://pantera.infopop.cc/top...and-roin-information
