I have a stock Buick 3.42 posi 8.5 in the car now and am currently in the middle of a build that should put the car in the low 10/high 9 second range with help from the bottle. Is it worth it to put money into the 8.5 (axles, gears, full spool, c clip elim, rear cover with axle brace tubes) or just sell it and put the money toward a 9 inch? Money is not easy to come by now days so I would prefer to spend it on what will last.