Medium duty 350s the same as car/truck 350s?

[urbex]

Been looking at some old C40/C50/C60 trucks, and see a good number of them have 350 engines in them. Are they the same as light duty car/truck engines, or some completely different animal only sharing the displacement?

I know some of the Ford medium duty engines are like that, such as the 429 - light duty 429s are almost 100% different than medium duty 429s, and virtually nothing interchanges between them.

 

[HankScorpio]

A lot of those small blocks had small valves. They made ok torque. I had one out of a mail truck in a k20 for a while. It worked pretty well until it threw a rod. There were lots of variations so its hard to say if they are the same or not. There is lots of interchange with the passenger stuff.

 

[sweetk30]

lots of them got good stuff like forged crank / rods / extra nickle and tin block . should be 4 bolt main .

now 366 and 427 tall deck big block were a bit different . but still share a lot and swap around . just 366 is its own and not much aftermarket love . 427 tall deck there is lots of stroker kits to take them out to the 540cid range .

 

[urbex]

I was really looking at it more from the perspective of if I buy one of these trucks, and the motor pops, whether I can run a car based motor or if I HAVE to start with a medium duty motor...though I probably didn't word the post well enough to convey that. Like will a car block bolt into the mounts/to the trans, or more importantly, if it's as easy to swap in a big block as it is to do in a square, lol. I know the car motors weren't designed to be run hard day in and day out, but I don't run these trucks like they were designed to be either. Aside from just being different, it's really about getting something that's older, AND is properly set up to be handling heavier payloads/trailers than a 50s/60s 1 ton pickup would have been.

My International is rated at 18K GVWR, which means I can easily toss my 4K pound truck camper on it, plus pull a 8K pound trailer load without stressing the components, albeit at a MUCH slower speed than modern trucks, lol.

 

[HankScorpio]

Yes, the 350 in the industrial trucks should bolt up to the same bellhousing and motor mounts as the BBC or SBC. I have also swapped heads on them without issue. Some medium duty trucks have a big round SAE bellhousing with an adapter to the GM pattern. They are easy to spot and it should still bolt up fine. Clutches and flywheels were often different but again should be interchangeable for different applications.

 

[79rustyk10]

I've heard some guys really like the medium duty trucks with a 327/350, but I wouldn't even look at one that didn't have a 427 myself.

 

[Bowtie85]

Just sold a 350 out of a c50 I had on the stand for a couple years. Numbers checked out to be the same year as the truck it came out of. The heads on the other hand came back as a target master.

That is the only useful yet mostly useless info I have.

I had a 80s add that mentioned the medium duty 350 and it’s features. Was kinda neat, if I come across it I’ll post it up.

 

[urbex]

I've heard some guys really like the medium duty trucks with a 327/350, but I wouldn't even look at one that didn't have a 427 myself.

Heh...the International has a 264ci 6 cylinder in it, and it seems to work fine for me, although it's definitely not screaming down the interstate at 80mph