I've converted some standard MGAs front clips to Twin Cam over the years. The main differences are: Inner front wheel wells: The best thing to start with are MGA 1600 as the "dimples" in them are closer to Twin Cam dimples. Considerable hammer and dolly work will make them appropriate. They also need to be extended a bit at the bottom in the back since they don't use the reinforcement panel (Moss 459-110, 459-115) that pushrod use. Then they need to be cut for the removable louvered panel. Here are some links showing how we did it years ago: Modifying the inner wheel wells part 1: http://www.eclecticmotorworks.com/sheptc21.html Modifying the inner wheel wells part 2: http://www.eclecticmotorworks.com/sheptc22.html Welding to the bottom of the inner front wheel wells: http://www.eclecticmotorworks.com/sheptc25.html Inner wheel wells welded in and cut/modified for louvered panels (got those from Jim Alcorn): http://www.eclecticmotorworks.com/hstc30.html Radiator Mounts: Since the radiator is a little forward in the car, the radiator mounts are different and mount to the inner wheel wells at a different location (somewhere over an inch, don't remember exactly). Making the mounts with a hammerform: http://www.eclecticmotorworks.com/sheptc23.html These can be spot or plug welded in place. The radiator duct panel is shorter than a pushrod panel to make room for the more-forward radiator. We've used the reproductions sold by Moss successfully This shows one after we punched oil cooler mounting holes into it and welded it in place: http://www.eclecticmotorworks.com/hstc47.html Several holes on the front bulkhead are in different locations, as well as the square knockouts for the pedals and master cylinders and the heater box aperture. There used to be reproduction bulkheads available (not sure anymore), or it's a matter of welding some holes shut and cutting new ones. These pictures are from one car we did that was badly wrecked, so we had to replicate a lot of Twin Cam specific parts including chassis brackets, etc. You can find much of it detailed under the heading "MGA Twin Cam - Sheetmetal Restoration" http://www.eclecticmotorworks.com/previous.html You have to scroll pretty far down the page (and it's an ugly page from 10+ years ago).

I hope this helps a little,
Carl Heideman
Eclectic Motorworks