If you have to buy one new, my suggestion is Tim Allen of Allen Motorsports on eBay he is either hp1350 or 1350hp. not sure which.
214-391-7562
My problem with the Dyno Flow eBay ad is that Dyno Flow claims to be the only authorised Dart Dealer on ebay and that claim is a lie, and is mis-leading advertising. Maybe they have changed it by niow but that is what it used to say. I did phone them last year and raked them over the coals about that lie.
Tom the Mod here has a Merlin Lite Block for sale.
Ed