He slight issue with my GU

[Clam_gutd42t]

G'day all.

Im Chris everyone calls me Clam.
I'm new to thee site, and hoping to get a little more info.
I own a 2000 gu wagon. Originally I had a 3.0 direct injection ZD30, since then I blew it up and put in a TD42 silvertop. with a highmount turbo, front mount intercooler and injection pump done to it, making respectable power. but the only issue I have left is, some times when I'm on the brakes hard and just as the car is stopping, the engine revs drop down about 150 pm, but its only brief until I take my foot off the break. I've ad me alternator checked (running the alternator vac pump and all) the braking system is fine. I had a rear calliper seazing up (common fault apparently). its collosal bad when the air con is on. and I was just wondering if anyone had some suggestions as to why the car might be doing this, my mechanic is scratching his head not having any ideas. So I'm hoping someone might have a idea or something I can try to fix it.

Cheers people, ~Clam

[threedogs]

Hi Clam might want to pop over to the intros first and say hello, its like a hand shake so we all get to know you,
No harm done and I think the 4.2 guys will be able to sort you out.