He said you can mix and match them with no problem. I can't remember the exact weights he said he used (something like 3x6g and 3x3g)- but he said it's best to experiment and choose the best ones.
I'm pretty much going on his word right now that they'll fit. But this seller is really nice and shipped me a new head for free. I would recommend him to anyone!
I am just waiting for a cheap or free electric impact wrench. Autozone wouldn't let me borrow theirs, harbor freight has them for $40 (I should have gotten one when they were on sale for $15!), and I don't want to get one off ebay.
Jalon JL50QT-18, 80cc conversion, 3x6g and 3x7g roller weights, 19mm keihin carb, port work, freeflow filter, custom license plate, neons!
I thought all these low price imact drivers would all be the same make, but with a different label on them. Apparently not, the Clarke CIR-13 easily came out top in tests, (though not compared with the RAC) and at £24.66 from Machine Mart, is cheaper than the RAC one from Argos. Link:- www.machinemart.co.uk/product.asp?w=1&p=060810013