Check with Gary Wallace at gwtrucks@yahoo.com He makes a T800 with either an internal or external air cleaner. Can't remember if he makes the T800W & T800H, though.
This might help in making that fuel injector pump:
http://public.fotki.com/modeltrucks25thscale/model_magazine_articles/car_modeller/cm09_sept_1991_cate/
Here's what it looks like in my Ford LN8000:
I've delt with Dennis a couple of times, and always had positive results. I guess all good things must come to an end.
Anyway, I've heard good things about these guys:
http://www.scalehobbyist.com/index.php