Posted by Charlie on Monday, November 20, 2000 at 02:44:19:
In Reply to: How about a 3.9V6 in Power Wagon? posted by George on Sunday, November 19, 2000 at 19:07:17:
I've been looking for a recent (0-3 yrs old) Vortec 4.3L V6 for my B1PW. It has a blown engine with a GM bellhousing and SM420, so any GM motor that's compatible with the bh is what I need. The 4.3 is of course small and short (shortness is key for re-powers, it's the biggest dimensional problem) and I think they're typically rated at 260 ft-lb and about 170-200 hp. They are used extensively in 1/2 ton pickups and share parts with the venerable 350/5.7. This truck is destined for a village with speeds never over 45, so 5.83s are what it will keep and no overdrive or giant tires will be used or needed (just 36" half worn 9.00R16 XLs). At 45 mph it'll be a bit over 2500 rpm, fine for that motor, should have good pull in 4th down to about 30 mph.
For road use on the North American road net, think about a 4.3 with a Ranger overdrive and a SM420 or 465 (0.73:1 ratio for the Ranger), or a NV4500 (usually 0.74:1 5th gear). Or 4.89s with just a 4 spd and oversized tires (2640 @ 60mph with direct top gear, 4.89s and 11.00R16 sized tires). Or if you really want performance coupled with stoutness and PTO availability, a DIRECT 5th gear NP540-541-542 (MUCH easier to find than OD versions) or direct Clark 280 series 5spd. Eaton/Fuller bought Clark and their current FS4205 A, B, C offer direct 5th; 6.99, 3.78, 2.13, 1.17 or 1.28, 1.00; or, 8.05, 4.23, 2.45, 1.48, 1.00
The 8.05 version behind a 4.3 Vortec (it would fit, there's lots of length room!) with 4.89s would be a killer rock crawler with 77:1 low 1st, even better than 73:1 stock.
Whatever you do, if you do a V6, don't go 4.89s, overdrive and big tires. 5th will be useless and gas mileage will actually drop. Do either 4.89s or OD but not both, even for highway use.
Charlie