Hi guys I am new here but figured I would ask a question. I have looked around and seen alot of great advice. I am not a car guy but I do have a hot rod boat . ok so here is my question I have a new 496 that I put togeter that makes 710 HP on 91 octane pump gas. I was out over the weekend and the oil temp was around 245 now I have been told that is to high. I have been told to keep it down under 230 as thats when oil starts to breakdown and varnish. I am running a big oil cooler that is fed directly from the lake or river I run in and the water temps are anywere from 60 to 85 degrees F after adding the cooler it only droped abput 10 degrees. so were should I run it??

I also run a multi weight oil 15/40 kendall and I notice that when the oil temp is around 245 when I drop to an idle the oil pressure drops to around 20 after running around 70 to 80 psi while in it. should I go to a straight 40 or 50 and loose the multie weight?

thanks
Shawn


Engine:
BBC 2 bolt block studded
eagle 4.25 4150 lightened crank
eagle 6.385 H-beam rods with Arp L-19 blots
JE forged pistons 4.310 bore 10.2 /1
AFR 325 heads with 2.30 intake and 1.88 exaust
custom solid roller .700 lift 109 lobe sep cam
morell soid roler lifters
Crower pushrods
Crane Gold Rockers 1.8 on intake and 1.7 on exaust
10 quart milidon Pan
Edel victor TR2 tunnel ram
2 600cfm blower carbs
made 710 HP @ 6100 and 689 TQ @ 5400 on 91 octain pump gas