68 El Camino Radiator and Oil Cooler

[Lynn]

Getting ready to do work on the El Camino.

Three issues:

1. Need a bigger radiator.
2. Want to add an oil cooler.
3. Need to lower the max oil pressure.

Engine: 350 bored .030. 10:1 compression, 186 heads with 1.94 intake valves. Roller cam with Morel lifters. Stock cast iron intake and Q-jet. Engine was built for torque; not high rpm.
Trans: 4L60E with stand alone controller.
Rear: 12bolt, 3:31

Radiator.
When I built this engine a few years ago, I ditched the original radiator (original 307 PG) in favor of a big tube plastic aluminum radiator. It is a factory A/C car, so the radiator is wider than the non A/C version. I use the trans cooler, but also have a supplemental cooler plumbed in with it.

I want to keep my factory style clutch fan and shroud set up. The only problem with the current radiator is it just isn't quite big enough. Runs too hot in 100 plus temps OR if I am hauling a big load on my car trailer. I think it is single one inch tubes.

I am fine with another plastic tank, aluminum core radiator. I just don't know what to order to make sure I get one with enough cooling capacity. Can I order for a big block? Do I just need to verify core size and car fitment? Would like to avoid sending parts back that don't fit.

Second issue: Oil cooler.
I have never installed an aftermarket oil cooler. What is simple, relatively inexpensive, easy to install, and will allow me to use the same oil filter I am currently using?

Third: lower oil pressure
When I start this engine cold, the oil pressure exceeds 80 to 85 psi. I specifically ordered a "high volume" oil pump, but not "high pressure". Pretty sure it is a Melling pump. I know I can cut down the spring; but how many coils do I cut off. Would like the oil pressure to max at 60 psi cold.

Any help appreciated