350 to 292 swap.

[TCK1]

Hello all, I’m new here. I was curious is anyone has done or has information on a 350 to 292 swap. I have an ‘81 k25 with a sm465, np205, with 3:73 gears, with 33” tires. I came across a c65 with a 292 that my grandpa owned. Im looking at rebuilding the 292. Im past the point of hot rodding around everywhere I go in my life. All I do is pull a 3 horse trailer around once a week. I was loooking for opinions on this swap or if you all think I would regret it. I’ve always liked the inline sixes, thought it would be cool to have grandpas old engine in my pickup. Didn’t know if a 292 would be any good with the setup I have. I was hoping the low end torque that the 292 would make up for that decrease in horsepower.

 

[mcarlo86]

Hello all, I’m new here. I was curious is anyone has done or has information on a 350 to 292 swap. I have an ‘81 k25 with a sm465, np205, with 3:73 gears, with 33” tires. I came across a c65 with a 292 that my grandpa owned. Im looking at rebuilding the 292. Im past the point of hot rodding around everywhere I go in my life. All I do is pull a 3 horse trailer around once a week. I was loooking for opinions on this swap or if you all think I would regret it. I’ve always liked the inline sixes, thought it would be cool to have grandpas old engine in my pickup. Didn’t know if a 292 would be any good with the setup I have. I was hoping the low end torque that the 292 would make up for that decrease in horsepower.

The 292 would work for what you are wanting to do. They do make decent off-idle torque and obviously were used in medium duty trucks for that reason. Low-end torque is the most important factor for pickups, especially if you are going to tow a little with it. Is there anything wrong with the 350? In reality it will be cheaper to rebuild the 350 than to overhaul a 292, but I understand the sentimental reasons for doing the swap. Check out 12bolt.com for lots of good info on Chevy 6 cylinder building ideas and parts.

 

[TCK1]

No the 350 is good. May get built into a 383 for my son when taken out though. Just didn’t know if I would be shooting myself in the foot for doing the swap.

 

[nvrenuf]

I know the motor mounts / frame stands are positioned differently on a 292 than a 250 or V8 (specifically the pass side). I believe the actual crossmember is different to accommodate the offset too.

 

[Memaloose]

I did a 292 to 350 swap in a '68 C/10 back in the '70's but don't remember a whole lot about it except the motor mount issue which wasn't hard but the 350 sat back a ways and needed a longer shroud.
The 292 was a good engine but was using oil when I bought it. I drove it for a year or two until it was using a quart every 70 miles. I installed a 0.030 over, 350 hp, 350 I built and wasn't sorry, it was a good swap. I sold it to a guy and a week later he ran it into a 48" diameter Douglas fir. He did save the engine but got hurt pretty bad, several broken bones. Better him than me.

 

[Shorty81]

That 292 mated to a sm465 is a great puller. We hauled a lot of grain in old Chevy C60 grain trucks years ago. I would do it.

 

[TCK1]

That is what this 292 is out of, but we hauled silage with it for years when I was growing up. The last time I remember this 292 running was about 10 years ago when we were using it as a feed truck for the cows in the back. It was running when it was parked. I’ve always liked the way the in-line six is sounded it reminds me of our John Deere 2510.

 

[MikeB]

GM lists the following torque specs for 1982 non-California models:
292: 215 lb/ft @ 1600 RPM
305: 240 lb/ft @ 2000 RPM
350: 275 lb/ft @ 1600 RPM (or 250 lb/ft @ 2800 RPM for over 8500 GVWR or HD emission controls)

Source: https://www.gm.com/content/dam/comp...its/chevrolet-trucks/1982-Chevrolet-Truck.pdf (Document page #11; pdf page #14)


Also, you will probably need to relocate (to existing holes) the motor mount frame brackets. Also, the motor mount-to-engine brackets for the 292 are probably different than the 350's. If you have a lot of patience, you can find the part numbers at GMPartsWiki.com.

This may actually be the page: http://www.gmpartswiki.com/getpage?pageid=55184

Wiring will also have to be extended or shortened, depending on the connection.

Have to say, it will be a lot of work, so I'd stick with a V-8, even a 305.

 

[MikeB]

Just realized the 292 specs I posted above may not apply to your C65 engine, but they are probably close.

 

[peats]

I would not make that swap. I see a lot of work with no real benefit.

 

[TCK1]

Thank you for all of your input.

 

[idahovette]

@TCK1 in the end of all this, it's YOUR truck, do with it what you want......nobody is writing the checks except you. where are you in Idaho, I'm in Weiser

 

[ali_c20]

The 292/250 was an engine option in 81 too so it should be no problem to get the right parts. 250 and 292 is the same block, the 292 is taller.
There are really cool parts out there for the line 6 engines.
I would swap it, sounds like a cool project to bring your grandpas engine back to work.

 

[nvrenuf]

@ali_c20 they are not the same block, there are several differences (fuel pump boss, lifter cover, pass side motor mount location, etc).

 

[ali_c20]

@ali_c20 they are not the same block, there are several differences (fuel pump boss, lifter cover, pass side motor mount location, etc).

Yes that's true. I was unprecise in my post. They are from the same family and a lot of parts interchange but they are not the same.