how about read "what else are you going to do sucka!!" you are screwed with out one so they have you by the curlies. the fact they sell you another 5k worth of bits doesn't bring the price down eh? yup, picking up or getting made a set of spacer could still happen as there are some good manifolds out there for 351's and i may still try one out in the future. does anyone make a really good airgap type yet? i have a low rise Holley street dom single plane for it now (apparently they are the best for LPG, and it will be on it a lot) but may look at changing in the future if one comes up at the right price. the spacers are the pain. like i said earlier if anyone can tell me how thick (.875 thou seems to unofficially pops up) and maybe basically the same as a gasket i have the potential to get it profile cut at one of my mates workshop for mates rates, so cost isnt too bad.

Edelbrock do a RPM Air Gap for the 351C, (p/n 7564) which i have here, can do for around $500.00, pm me if your keen.
They do a Performer manifold for the 400, but I havent seen one, and i have no idea on the price. The rpm air gap would be a nicer piece though, you just need to get the spacers.

I did a bit of hunting for the manifold spacers. Weiand have stopped making there kit, (p/n 8205) but there may be some around somewhere. Edelbrock no longer make this kit either. This mob http://www.pricemotorsport.com/ makes them, but they look a bit expensive.
I'm sure you could have them made locally for a lot less $$$. Tidy looking part, though.
Good luck.

Anything to do with low volume custom manifolds that are made by a company will cost big $$$, so they can make a big profit for their efforts. Higher volumes mean lower prices because they still have the profit via volume sales.

Unless you get someone in their backyard that can make them up & doesn't want a huge profit margin. Like a guy i know making up custom extractors for mighty boy's, $150 ready to bolt on. Exhaust shops want 4 times that!

Cheers

ToranaGuy

thats the supplier i mention earlier in this topic. looks great but a bit expensive. spacer plates and a turkey pan gasket would do the same thing. trust me, i've been looking for ages and those Holley units haven't been done for a while. i saw a set on Ebay australia with some other things nearly 2 years back and they went through the roof. you'd think they were made of gold. something tells me that if they are that handy they should still be made, but obviously in the states if you dont shift 100 a week she's a no-go

to toranaguy- back when i was in Shebangabang (NZ) through friends with machine shops, i would have had access to all sorts of wonderous machines and with a bit of mucking around we could build something like a blower manifold easy. i hear what you are saying about extractors. try getting a set for a 72 galaxie. they look at you, say they will have to make it and the price is somewhere between $850-1000. i've got a set off ebay for $110 so with a bit of professional butchery i will get that fitting. i couldn't even get a kit for under $400.