Ring Gear Size I think you're asking the overall diameter in inches , next question will be how many bolt holes so you can go junkyard shopping and get a better final drive ratio ~ fergeddaboutit ~ GM didn't make any other vehicles using this size ring gear I ever heard about and i've been on these things since the 60's The good news it : patric's makes a nifty 3.55 R & P set you can buy , I have one in my '49 and my mystery 235 pushes it along @ 65 ~ 70 MPH just fine . Of course , if you were just asking the ratio , most were 4.11 but some were lower than that .
Ya i was asking the overall diameter in inches so that i could get a replacement ring and pinon gear but if this was the only model those rear ends came in im definatly gonna be better off to get another complete rear end and make it work from there. i believe mine has 3.90's in it now and i thought the axles were something like 18 spline or something.
Why ? If it has 3.90 ratio now , it should easily go 70 MPH without straining the engine , be it a 6 or 8 cylinder job...