Posted by Brian in Oregon on Tuesday, November 07, 2000 at 20:13:34:
As many of you know, Ray Suiter of Helitool is making conversion kits to put small block Mopar V-8's into the M37 and PW.
I'm going with a 318 and the original NP420, since I want to use the PTO winch, even though it is non-synchro in 1st & 2nd. (An NP435 would be even easier to swap in).
The kit consists of two parts. The engine kit, and the trans kit. This allows flexibility for different combinations. Eventually a 360 kit will be available, as well as an NP425 (both of which have been done for the PW as seen on Ray's site).
Except for the very slight notching of the frame to clear the drivers side exhaust manifold, and a bit on a mount near the trans, there is no permanent alteration of the M37. You can readily restore the truck with a flathead if you desire.
The kit has everything you need except the engine, flywheel, starter, bellhousing, belt and flex fan. It has the motor mounts, hoses, throttle linkage, vibration isolators and various little parts.
The trans kit will have the altered flywheel, pilot bushing, and clutch fork alteration pieces, plus the NP420 to NP435 bellhousing adaptor plate, which is also a trans to frame mount as well. This part of the kit requires some minor alteration of the clutch fork, bellhousing and clutch linkage. I don't see why anyone cannot do this themselves, but a machine shop or a knowledgable friend can certainly do it too.
Anyway, the motor mounts are exactly what you'd expect on an M37 - rugged and beefy. They are thicker than the frame itself. These are God's own motor mounts. Note that these fit the 273, 318 & 340. The 360 has the rear motor mount ears slightly moved and thus this particular kit won't fit the 360.
The throttle linkage is well built and rugged.
And talk about attention to detail - all the bolts, washers, lockwashers and nuts are cadmium plated, plus even the hoses AND hose clamps are included.
Having done racing, I've seen a lot of conversion kits that were Mousey Micked. That is definitely not the case here. This is not only a fairly simple drop in, but one that looks as good as it functions. And the cost is quite reasonable, especially compared to the time needed to properly engineer a conversion like this. It is also far less expensive than some 318 conversion kits I recall seeing in older issues of Military Vehicles Magazine.
The NP420 portion of the conversion should arrive sometime this month.
I'll post more as I make progress. There are a few parts that have to be furnished, such as an extra passenger side exhaust manifold for the drivers side (clearance issue with the normal drivers side exhaust), plus a rear sump truck pan, dipstick and pickup. Right now I've opened up the motor for inspection to see if it needs anything besides fresh gaskets.
You can see photos of this conversion kit at:
http://www.helitool.com