Good evening Boris,

You're not stuck looking for a wet manifold, just drill and tap a later dry manifold. Most of the aftermarket manifold offered for the early Hemi's will have a dimple cast at the proper spot on the mounting flange.

Look at http://www.hothemiheads.com for a broad choice of early Hemi manifolds.

The same seller of that manifold has another for sale right now which includes the velocity stacks. I had planned on bidding, then got distracted at work at the last minute. My plan was to convert it to EFI with the Megasquirt as well.

If you'd be happy with a plane jane four barrel there's one for sale on eBay for $10 or so. Just tap the holes and connect to a standard marine style remote thermostat.

Regards, Mark