Most definately the aluminum cylinders will go a long way to help make a set of autocraft heads more streetable with the extra cooling, no doubt about it.
What kind of bore size do you think would be ideal? What kind of wall thicknesses do you want to run? Our 102mm Type 4 Nickies have a wall thickness of 6 1/2 mm for comparison. 94mm Type 1 Nickies have a wall thickness of 3 3/4 mm on the other hand and they've had great success. Hopefully Jake will chime in some time with some figures from his first dyno run of a Type 1 Nickies equipped monster he built :-)
And about quantities- we'll make a set even if only one person wants to step forward to the plate- we'll more than happily eat the programming and added tooling. It would be great to have a 100% all aluminum T5 :-)
Take care,
Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance