3-4 really has to do with your A/C system and ETG... are you injected or carb'ed?
How much heat are your heads dealing with at the exhaust, under full load?
If you don't know, any answer is a best guess...
If you run a quality thermal control switch and a pair of good quality electric fans... it really comes down to what your engine likes in the temps you drive in TX. The fluid dynamics to estimate what the core required is very lengthly. Turbo guys can spend $$$ on getting it right.
I just pulled a 454 core from a 99' K2500 with Rad mounts in excellent condition, zero leaks.
It only uses a single 12" fan to cool A/C and everything, oil cooler, trans cooler etc...
Towing and everything, this BBC never blew a radiator, AZ to MT every year.
Keep in mind, the core count can be misleading... The quality OEM and High quality aftermarket plastic tank/aluminized cores, can be single core and equal aftermarket double cores... the aluminum core metallurgy really matters.
Thickness of the crimps on plastic tanks make a difference, as well as the plastic casting quality too.
Unless you mic the aluminum crimps... you have no idea what you are buying online...
OSC makes good replacement OEM tanks... thick crimps. They are known to last 10 years in sever climates...
The hand welded units... not even close.
$800-$1200 brand name aluminum Race radiators are only rated for 2 years.
The thermal switch sensors', with adjustable temperature and a fan relay, you'll have to source on your own. If I can find the brand I bought for my turbo Nissan's, I'll post it here. Something tells me they were sourced from Pegasus, from the guys who use them for cooling circle track Outlaw cars...
Probably the best solution for anyone living in the south with extreme heat loads and a BBC?
