ChuckN
Full Access Member
- Joined
- Nov 8, 2022
- Posts
- 2,084
- Reaction score
- 7,643
- Location
- Bellinham, WA
- First Name
- Chad
- Truck Year
- 1981
- Truck Model
- C10
- Engine Size
- 350
So rather than keep spamming the “what have you done to your square body lately” thread, I figured I’d continue the conversation here. So, here it goes.
For those that may have not read, I bought my truck a few years ago. Allegedly, had a “ 327/350 hp.” The guy I bought the truck from had purchased it from an engine builder, and it was rebuilt and only broken in on the stand. He then lost interest in it, needed an engine to put in my truck, and then sold it with it. He had never looked inside the engine.
Aside from some oily spark plug issues, that I had assumed was valve seals, the engine actually ran pretty good for the last few years. Aside from some carburetor tuning issues that refuse to get sorted out, probably because the cam is too big for the engine. I have no idea what the cam is, but I’ve owned a L79 cam in another 327, and this ain’t that.
I had assumed that it was a 350 because that’s what the block was stamped as (1975 0010) and was stamped .030 on top of the piston when I looked at it with a bore scope (then a 355). While I was in there, I could see there was some crosshatching. A good sign to me at the time.
But the engine never really lived up to what it was supposed to be, it wasn’t very torquey and wouldn’t even light up the rear tires even though it sounded nasty. Fast-forward to these days, and I bought a set of really nice aluminum cylinder heads to put on it since I wanted to eventually take it to the strip and improve the performance.
A couple days ago, I pulled the heads and found that the cylinders didn’t look very good, probably an amateur job at best. A couple bores have some very irregular wear patterns, and one shop suggested it looked like it had a head gasket leak previously and a bore done poorly. I added up a theoretical compression ratio, and it came out to 8.8:1 with the camel hump heads and flat top pistons with four valve reliefs. So, shorter stroke and low compression? Well, that checks out now.
At this juncture, I have been considering an LS swap vs making the existing engine what I want it to be. Today, I have an appointment with a shop to look at a used LS, and after that, a machine shop to cover what it could look like to redo what I have. But I wouldn’t be able to afford to rebuild a LS and to buy the parts to complete to swap for a long time with the budget I have.
At this point many members (and I thank you all wholeheartedly) have chimed in with idea and support and a little “why the hell would you do that?” to keep me centered and I appreciate all of that.
So let’s do this.
At this point, I have no interest in keeping the 327 as is, so let’s get that out of the way right now. There’s nothing wrong with that kind of engine, but I’m only doing this once so I’m doing it the way I want. Which, unless the LS seller comes way down and offers some accoutrements to come with it to make it more doable (a fantastical scenario), it’s unlikely to happen.
Enter the 383. There’s no reason to just put it back to a 350- both financially and for performance. The cost would be relatively equal. I couldn’t believe how cheap a reputable rotating assembly is, and thanks to all for pointing that out with links, etc.
So here we are, and thanks for reading. I’ll post as things progress which will be intermittent as expected.
Cheers,
Chad
For those that may have not read, I bought my truck a few years ago. Allegedly, had a “ 327/350 hp.” The guy I bought the truck from had purchased it from an engine builder, and it was rebuilt and only broken in on the stand. He then lost interest in it, needed an engine to put in my truck, and then sold it with it. He had never looked inside the engine.
You must be registered for see images attach
Aside from some oily spark plug issues, that I had assumed was valve seals, the engine actually ran pretty good for the last few years. Aside from some carburetor tuning issues that refuse to get sorted out, probably because the cam is too big for the engine. I have no idea what the cam is, but I’ve owned a L79 cam in another 327, and this ain’t that.
I had assumed that it was a 350 because that’s what the block was stamped as (1975 0010) and was stamped .030 on top of the piston when I looked at it with a bore scope (then a 355). While I was in there, I could see there was some crosshatching. A good sign to me at the time.
But the engine never really lived up to what it was supposed to be, it wasn’t very torquey and wouldn’t even light up the rear tires even though it sounded nasty. Fast-forward to these days, and I bought a set of really nice aluminum cylinder heads to put on it since I wanted to eventually take it to the strip and improve the performance.
A couple days ago, I pulled the heads and found that the cylinders didn’t look very good, probably an amateur job at best. A couple bores have some very irregular wear patterns, and one shop suggested it looked like it had a head gasket leak previously and a bore done poorly. I added up a theoretical compression ratio, and it came out to 8.8:1 with the camel hump heads and flat top pistons with four valve reliefs. So, shorter stroke and low compression? Well, that checks out now.
You must be registered for see images attach
At this juncture, I have been considering an LS swap vs making the existing engine what I want it to be. Today, I have an appointment with a shop to look at a used LS, and after that, a machine shop to cover what it could look like to redo what I have. But I wouldn’t be able to afford to rebuild a LS and to buy the parts to complete to swap for a long time with the budget I have.
At this point many members (and I thank you all wholeheartedly) have chimed in with idea and support and a little “why the hell would you do that?” to keep me centered and I appreciate all of that.
So let’s do this.
At this point, I have no interest in keeping the 327 as is, so let’s get that out of the way right now. There’s nothing wrong with that kind of engine, but I’m only doing this once so I’m doing it the way I want. Which, unless the LS seller comes way down and offers some accoutrements to come with it to make it more doable (a fantastical scenario), it’s unlikely to happen.
Enter the 383. There’s no reason to just put it back to a 350- both financially and for performance. The cost would be relatively equal. I couldn’t believe how cheap a reputable rotating assembly is, and thanks to all for pointing that out with links, etc.
So here we are, and thanks for reading. I’ll post as things progress which will be intermittent as expected.
Cheers,
Chad