B&M trick shift. we like the trick shift as it has a higher boiling point and lubes better than regular dexron or type F. we ran 3-4 seasons without a transmission cooler on our 4 link dragster with a 540 bbc. didn't have any problems unless back to back multiple runs and ended up knocking a bearing out of the converter and nuked everything. after that,for last season, we installed a cooler with fan.
tried some hyd fluid from local implement and it ended up tearing the clutch lining off a band new low gear band.