Ok, I have a 1986 Iroc-z.... The previous owner pulled out the lil ol 305 tpi and he rebuilt a 350 (.030 bore, Not sure if he rebuilt the 70s smog heads...)

I recently put in a covans autometer panel, and changed the oil for the first time... I changed the oil (he had a wix filter, not sure of the weight of oil...) I put on a K&N filter and some valvoline 20w-50, This was a mistake!!!! I started it up and my oil psi gauge went to 60psi, I about wet my pants so i shut it off, thought about it for a while... Turned it back on and let it warm up idleing.. It got to 180 degrees and its still at 57psi.... This is wayyyy to high in my opinion. I should have put in 10w-30 or 5w-30 huh? That 20w-50 that the parts guy reccomended for a rebuilt 350 is like syrup not oil....

I also told him that when i turn the car on every morning it has a poof of oil smoke before the oil change.... It would never burn oil during driving or when it would idle for long periods of time...

The car runs at a solid 180-200 degrees. What could be causing the oil burn at immediate start up and never any other time..What weight oil should i put in this rebuilt (only the block was rebuilt i assume....) engine..

Thanks a ton. If there is anything I can do to kill the oil burn at startup that would be great~!

 

My oil pressure gauge goes up to 80 psi with 10W-30. Just depends upon the oil pump.

10W-30 should be fine for a normal "tight" 350.

The puff of smoke at start-up is oil getting past the valve stems. Very common problem. It's either from the valve stem seals being worn or hard/cracked, or worn valve guides.

You'll be replacing the 70's smog heads with Vortecs anyway, right?