After months of trying to find the sweet spot on my set up I've went from the stock 3+1 to a 3+2 and 45 shock oil up front and 40 in the rear but I think 37.5 would be ok. I've used the 0 offset shock bottoms and ride height of 26 rear and 27.5 front. Grey spring in the front and white rear. I was able to eliminate the use of a brick pack and run a shorty for major weight loss On our high grip clay track with slicks it was great.