The 2 intakes are the same as you described with the only difference being the seprated runners and lack of heat cross over on the RPM. All engines like a cool ense clean air fuel charge and if I was running the street in the chilly weather, I'll run an intake with a heat cross over. It's worth the quicker warm up time and reduction in plug fouling over the few HP it's worth.
MAL, if I didn't have ethier and the engine build was a "Hot Rod-ish" in style like/type build without cold driving, the airgap would be the choice.
Also, since this is a 400+ stroker, I would guess this is in the toy car rather than the everyday driver. You'll just have to say to yourself if the expense of the Air-Gap is worth the extra power/wow factor etc.......
I just picked up a LD340 for my 360 build for my daily driver. A 3800+ lbs. '79 Dodge Magnum. It was alot cheaper than a new RPM and it's a old school period correct part.
