Bracket racing and looking for parasitic losses at engine , 727 and general drivetrain:
What are the thinnest gear oils being used safely with spools/ 8.75 rears?
Best trans fluids?
Do we have trans pumps that are highly effieciant ?
I’m in the south ( Texas ) wondering about hp loss on engine oils as 30 years ago I ran 20w50 and don’t believe that’s needed any more.

I’m looking for all the “ little things” that can be done to reduce parasitic losses.

Thanks,
Rusty

I run 5W20 WT Valvoline non synthetic oil in my bracket motor and 75x80 Redline shock proof in the Dana 60 rear end, type F fluid, any brand, in the tranny

Hot weather I would keep my thicker stuff for bracket car
Get lucky go 6 rounds and then you are pushing oil to the limit--NHRA guys are way different form bracket car--stay safe go .007 slower --right?
I love thin in the rears --synthetics actually run much cooler than std oil in rears for Sure--No harm there but you get to round 7 in hot Texas and your thin stuff is about to let you down unless all is perfect and in a bracket car there is just no reason to hunt there for that tiny return IMO
Your Heros down there Rher Morrison says 10wx30 in race engine but it is really all about bearing clearances--Gibbs Oil has the best tech available for your original question You have .004 on the mains then water oil will not do the job just like if you have .002 20w50 is not best
Gibbs tech is great--call them but know your bearing clearances for best answer and ...fuel matters--you run alky then conversation has to start over
Bracket car --run safe --
NHRA stocker? run that 0wwhatever LOL
Good Luck hope you wax some folks next year