For the 914-6, are the oem heat exchangers still available? If not, who sells aftermarket heat exchangers for the 914-6?

You can find OEM ones every now and again, but if you want ones that are in good shape you should go aftermarket. There are a few different companies that make them, but they must be made out of gold as they are over $1500.

readily available but expensive!~

I've got a pair that were just refinished. Sandblasted, Expert welded, POR-20 Aluminum finish.

I'll also have a good set of "Take-offs" avail in July. These also have an extra heat-duct tube on the R-side...which is used for MFI cold start enrichment.
If Eric does'nt sell you his, PM me and perhaps I can hook you up.
BTW, all 9146HBs came with tiny exhaust ports...prolly good up thru 2.7 L engines.
Unless you really need the heat, you should go with larger dia headers on 3.2/ 3.6/ 3.8 engines.
Marty

I just placed an order for GHL's with heat...I'll let folks know what I think when I get them (should be about two weeks).