348 in a 1957 Chevy NAPCO


Well Known Member
I have my 348 back from the machine shop and am almost done assembling it. It will be installed in a 1957 Chevy NAPCO truck. From what I have been able to glean from my research, I should expect the driver's side exhaust to potentially interfere with the steering box. I was wondering if anyone had experience with the Sanderson shorty headers and if that would resolve the issue. Not having done the swap before, it seems the stock headers are pretty tight to the engine anyway.
Well, I better be able to see pictures of THIS ONE ! :deal:bow

If you build your own 1 5/8" or 1 3/4" headers for it, clearance can be had.
The Sandersons may require putting a little dimple in them.

blown 409

Well Known Member
i have a 348 in a 59 1 ton napco 4x4 put it in years ago, has 409 manifolds , ground the 1 next to steering box, still have truck,

Phil Reed

Well Seasoned Member
Supporting Member 10
What do you mean, 348 in a 59 1 ton 4WD ????
Come on, man... that's a freaking truck... I gotta see pictures ! ! !
Hey Tim..................me thinks you have trading material for a WHOLE BUNCH of new 409 intake manifolds!!!!!!!!!!!!!!!!!!!! I think we've found Aubrey's soft spot!!!!!!!!!!!!!!!!!!

blown 409

Well Known Member
i used to truck pull it a little, 348 with Jahns 11.5 pistons 409 817 heads, 560 lift hyd cam, 6 pack, 2 1/2 straight pipes, 4 spd posi rear 456 gears , 38 M/T tire on street, 33 m/ts for pulling, this is ony photo i have, but truck is still here with all the hot rods, have had truck 25 + years Tim 59 chev 1 ton 001.jpg


Well Known Member
My 348 motor is about done. Another week or two when it gets warmer here in Minnesota, I'll begin the process of
removing the 283 and wrestling the 348 in its place. I'm hoping it isn't too bad, I anticipate the steering box header issue.
I'm sure there will be others. I do want to thank everyone for their help along the way, it not only made the build possible, but
made me feel a lot better about "doing the right thing."
engine front.jpg


Well Known Member
Supporting Member 9
That will look good in your 57!
I did a 235 to 348 swap many years ago in a 57 NAPCO pickup. I wish I had kept it.


Well Known Member
I have the 348 installed in the truck. My next issue is the radiator. The original radiator (new) was a for a V8 motor (283), no shroud.
Any opinions as to whether this radiator will do the job for the 348?


Well Known Member
Is it a two or three core? I'm more familiar with the 60-66 models, but they had a two core and a hd radiator that was optioned in our years (60-66) that was a three core.