What pressure rad cap do I need?

How many pounds rad cap should I use on my 59 chevy with a 235 with a 3 row rad. (New core, original tanks)

Thanks,
Clint

 

Original heater core?
That's just another weak old radiator waiting to toss it's cookies all over your passenger's feet.
If so, I'd use a 7#

 

I bypassed the heater for now because the first time I filled up the rad, the heater leaked all over the place so the heater will need to be recored as well. The rad is recently recored with a new 3 row.

I currently don't have a recovery system, just the tube that dumps on the ground, but I would like to get one in the future. I'm expecting that when I go to a recovery system I'll need a different pressure cap, but any idea of what I would need right now?

 

Just put the recovery type cap on it.
They have two rubber seals one on the spring loaded part and one around the cap itself.
Then just run that overflow hose into and to the bottom of about a quart or bigger container and your recovered!
(I'm using the water bottle off a bicycle on my truck but it's justa bit small on capacity.)