Popping while turning after complete overhaul.

Hello Everyone!

I hope everyone's Christmas and New Years was a blast!

I have a popping question on a..... 1970 340 Dart Swinger.

I just recently had everything under the front end replaced except.....
the torsion bars, lower control arms, and spindles with new parts. I put on Hotchkis sway bars front and rear, all new poly bushings, shocks, ball joints, etc....

Now one question I have and correct me if im wrong but.... the guys swear my car was a slant 6 and someone put the motor in it later.
The thing is I have the build sheet that says its a 340. All the numbers from my vin my finder tag and build sheet match. and all say its a 340.
So the guys that did my car had to order an A arm and it came with the lager ball joint ( he said he ordered it for a 340) so they sent my spindles out to get drilled out bigger to fit the larger joint but....

Didn't all 340s in 1970 come with the smaller joints?

All that being said. I'm getting a popping turning hard left and right.

Could this be because they reamed my spindles?