Did I choose the wring radiator?

[Greasey Harley]

I recently built a 350 for my k10. Bumped the compression to 9.5:1 and added some mild mods.
I installed a 4 row radiator and corresponding shroud. Problem is, i just went outside to warm up the truck (28* F right now), and after about 8 minutes, the heater is still blowing luke warm. it has a 195* T-stat. Is this what I can expect from the bigger rad? I guess I never had a small block with a big radiator, at least not one I drove in the winter.
Thinking about covering part of the radiator or reinstalling the original radiator. This is a hunting rig and heat is important.

What's your $.02?