Posted by Greg Coffin [172.68.3.52] on Saturday, November 15, 2025 at 09:44:37 :
In Reply to: Re: Repower 1/2 ton closed cab wc12 posted by Dave Horvath [172.70.175.82] on Saturday, November 15, 2025 at 08:37:15 :
I've gone 2 different routes here.
First was a 318 in my 6x6. With the short water pump it fits very nicely between the radiator and the firewall. Lots of power and RPM range. It really wants to go once it hits 3000 rpm. If I were going to do it again I'd go with fuel injection, either with a 318 Magnum engine, or with a Holly Sniper kit.
Second was a draw-through turbo on the stock 230 in our M37. It puts out the same HP as a 318, is very driveable, and really goes! We only run 4lbs of boost. It doesn't have the same RPM range as the 318, but I don't miss it.
Most of the noise you get in these trucks is from the transfer case and from the stock engine fan. I'd replace the NP200 with a NP205 and leave the rest as it is. A flex fan will quiet down the engine a lot.
I sell a power brake kit that keeps the original brake pedal, and I'm working on a hydraulic clutch kit that keeps the original clutch pedal (if you change out the engine).