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Hagerty Employee

Piston Slap: From Thriftmaster to a big-cube six shooter?

Is it possible to engine swap a 235 Chevy to a later-model 250 inline-six Chevy in my original factory, frame stock steering box, straight-axle 1957 Chevy pickup truck? Sajeev answers: Yes, because anything is possible when it comes to modifying a classic vehicle.

Why wouldn't you use a small block V8? Also period correct, and a lot better engine.
Before I did something radical like changing a frame crossmember, I'd think about making adapters, for both the engine and transmission.
How 'bout swapping in electric wndshield wipers, while you're at it. Also period correct.
New Driver

They have the same bell housing pattern.
They are both rear sump pans.
The motor mounts are simple, and would be an easy fab job.
But the 250 i6 is not easily hppped up, if that’s what you’re thinking.
The 283 v8 came out in 1957, find one of those, or any other SBC. Motor mounts are available on line.
New Driver

An excellent resource for GM inline sixes is Langdon's Stovebolt Sixes. Tom Langdon is a retired GM engineer in Detroit who is passionate about inline sixes and is a wealth of information and his products are high quality.
Pit Crew

Be aware that Tom, although quite expert with regards to the Stovebolt Sixes, can be somewhat unpredictable with regards to product support.

While restoring my first car (55 Bel Air - 19 month project), which I bought for $175 in 1966, I had a performance shop rework the stock 235 cid into something a little more interesting.

Amongst other items, I sourced two 32/34 Webers from Tom, however when I asked for assistance in locating the jets and associated paraphernalia, he told me to "go fish" and said that he had no interest in helping me. (BTW, Pierce Manifolds has great support for said Webers.)


Reminds me of my neighbor's '67 C10. It's an old Montana farm truck. He rebuilt the 292 and after running it for a summer it developed piston slap. I helped him get the engine back out of the truck. I stopped by a few days later and he said he figured out the problem and had it all fixed. I laughed out loud when I saw the solution. It was a 540 cubic inch BBC engine and 6 speed. Problem solved!