I have a 1995 GMC Jimmy 4.3 4x4 with 190,000 miles on her. Runs great, but starts a little hard ESPECIALLY when the climates cold, almost like there's not a lot of compression built up. Last year, in below 0 weather, even with lighter oil, it takes forever to get it started, or it floods out, or by that time I lose my battery.

Do you have to have platinum spark plugs??? I've changed out plugs, wires, spider gear, gas tank, fuel pump and sender......never any codes. It does start in the summer, but not always on the first try, and I fear getting to work up north here when the weather can get well below 0 degrees.

So, since the '95 is a very expensive motor, and SUPPOSEDLY it's the only engine they say you can use, I'm wondering why you couldn't use another year 4.3 and switch over intakes and distributor???? Is there something I'm missing here??? Don't want a V-8, just a regular old 4.3 Vortec that isn't so expensive from the salvage yards.

 

I understand there are several reasons. The 95 was a change over year. I believe crank senors are different & for some reason to switch them over isn't easy. I believe 95 used both the OBD I & II systems.
Anyway, if your flooding an fuel injection system then you have a fuel problem like a pressure regulator or a leak somewhere.
Why not pull a compression test that will tell you a lot. As for Platinum Plugs if the OEM were Platinum then, Yes. It has been suggested several times here to use AC DELCO Plugs.

 

I had a '95 with similar symptoms (not quite so many miles) and it was the EGR. Carbon prevented it from closing completely and that produced a vacuum leak. Cleaning the pintle fixed the problem but it would return after several 1000 miles and require another cleaning.
As a quick crutch, try cranking for only a few seconds then shut off the key and immediately crank again. This puts a second starting pulse of fuel into the intake. My '95 would start quickly this way even when the EGR was crudded up. A long initial crank never worked.
Hope this helps.