... Hi all, I have a '72 which I'm rebuilding, I would like to drop my 351c into it, but hate the auto box, the bellhousings look the same, does the original, 4 speed manual box bolt straight onto the 351c? more importantly, the flywheel? what I'm basically asking is, can I take the original box, with flywheel and bolt it straight onto my cleveland? and what are the shortfalls? ... I'm South African, so please bare in mind that spares etc. are impossible to come by...

 

What engine did the 72 have ?

 

I believe the C has the same bell as the 300 and the 302.





John

 

Yes, the "C" is the same as any small block. It's the "M" that is the big block pattern.

What motor was in the truck? 302?

 

The 351C (and be sure it's really a 351C, not a 351M as they look very much the same but are actually very different) will interchange with a late 289/early 302/351W in many ways, so if you have access to a 302/351W for parts you're good to go. Block bolt patterns are the same, engine mounts are the same, and both are externally balanced using an imbalance of 28oz. so the flywheels will interchange as well (provided you have the proper tooth count-be sure to count and check.) When I say late 289/early 302 I'm talking about 289 from mid-1965 to 1967 (earlier 289s had a 5-bolt bellhousing, changed to 6-bolt in 1965) and early 302 means 1968 to 1980 (changed to 50oz imbalance in about 1981.)

If your original engine is an FE than you're out of luck, the flywheel, motor mounts and bellhousing won't fit. I don't know how S.A. trucks came equipped back then, was it built in Australia?

BTW, I put a 351C in my '72 a number of years ago, but with an auto since that's how the truck was originally equipped. It was a very easy swap, almost a straight bolt-in even though the original engine was a 390. I did have to change the engine perches and swap in a different driveshaft but as I recall that was about the worst of it.

 

...351 clevelands are, for unknown reasons, relatively abundant here in SA, mine's definitely that... I've removed the original straight six from the truck ( and the FMX off the 351), and from basic "face to face" comparisons, it would appear the entire orignal assembly, flywheel and bellhousing, are straightforward bolt ons, the next question arises in the starter motor mountings, I built a cobra a while back using a 351c, and had to place a spacer between the starter and the bellhousing, otherwise the bendix couldn't disengage fully... you should've seen what it did to the first starter I fitted... utterly destroyed...

 

Here's the rub on that plan...the inline 6 (I'm assuming 300 CID) flywheel will bolt right up to the 351C but is zero imbalance so you'll wind up with a nasty vibration. You'll have to source a 351W or 320 flywheel as I mentioned above. But yes, the bellhousing should bolt right up.