1967 C10 Truck 7.4L Upgrade

[josuito]

Hello guys. I have a few questions for you.
I have a 1967 C10 short bed step side small rear window truck converted to 5 lugs that I've been driving and upgrading for more than 10 years. I started with a 6 cylinder, then to a 350 and now I think I finally got the right engine for now right, it's a 1998 7.4L (454) Chevy Vortec Engine with a 4L80E automatic transmission. I like carburetors on engines, I'm ok driving my wifys SUV for fuel injected rides. I'm not an expert but I can assemble parts.


So far I got to the following parts:
1x Weiand 8122WND - Weiand Street Warrior intake Manifolds
1x Weiand Street Warrior intake Manifold 8122WND
1x Weiand 9006 - Weiand Carburetor Sealing Plates
1x Edelbrock 650 CFM Carburetor
1x Summit Racing SUM-G1575HS - Summit Racing® Stainless Steel Intake Manifold Bolt Kits
1x Summit Racing SUM-359-180 - Summit Racing® Thermostats
1x Fel-Pro SFLMS90240 - Fel-Pro Intake Manifold Gaskets
1x Mr. Gasket 2661 - Mr. Gasket Chrome Plated O-Ring Water Necks
1x Fel-Pro SFL70194 - Fel-Pro Distributor Base Gaskets
1x 3 Row Radiator with 2 fans that fits my truck
1x Custom Shaft


Parts I need but I don't know how where to get them:
1- Something that turns my fans on-off when it gets to the right temperature for those engines.
2- Transmission controller that works with my column shifter. (Do I have to change transmission?)
3- I friend told I may need to change the original differential gears to be stronger and with a different gear ratio, I have no clue.

Any feedback will be much appreciated.