340 intake on a 318?

You can throw up all the excuses you want, the fact remains, Chrysler did it and didn't think anything of it. With a 318 built for performance with a good ignition curve, decent gears, and in a light A body It'll never be noticed.....and wasn't in much milder and much higher geared heavier vehicles. It's just a non issue. If you had a bog with the "mismatch" as you call it, I can promise you it was somewhere else.
I had a 77 D-200 4 Door, with a 318 ( not the same one mentioned in a different post) in o6 till o8. Daily driver. Same Lil intake, ran an eddy and then Holley. 4:30 Dana, 727., stock mannys on the out, That Truck HANDLED just like my Bros tricked out Dak R/T. And, it LOVED PAIN! No BS She Pulled HARD! I didn't build the mill ( got her from a redneck dude who's Grandpa built it, 500 bucks, sitting on the Last Farm in Carrollwood, and got it running) picked it's Sis outta there too. 700 for a club cab 400 . Lost my *** on that one. Rotted up. BAD. Should have never traded her. Gas was over 4 bucks a gallon, that's to obozo. The real estate/ building market SHOTOUT in FL. So I traded Her ( and a Lil $) for an 01 Dak sport 4.7 5 spd w ac. Cool truck, but.....