[Bored&Stroked]

RE: Ross Pistons

I definitely prefer modern metric ring packages over the old Grant/Hastings stuff.

I've used both TotalSeal rings (worked really well) and also other metric ring packs in 1.5, 1.5, 3.0 sizes. There are only certain stocking piston sizes that can be bought with metric rings. BUT, if you call their sales support crew, you can discuss your minimum bore size and then look at the available metric ring sizes and they'll make a custom piston diameter to match the rings. This is what I tend to do these days.

If you go through their sales folks (see if a guy named 'Ed' is still there - he is very helpful), you'll usually see only a small upcharge (like $40 or so) for a custom piston size.
Then you can go to places like Summit Racing and reference the Sales Engineer and have them order the right stuff for you (they'll probably call Ed) - getting the decent price from Summit (plus the up charge).

The metric rings result is less friction loss, are made from better materials (moly top ring) - no reason to NOT use them. As noted above, my resulting ring pack is usually 1.5, 1.5, 3.0 mm . . . though sometimes the top rings might be 1.2 or 1.5.

You can do a bit of research before you call them and look at common metric ring sizes that are close to what you want to bore too - then convert to inches if you need to see what sizes are available as compared to "normal" USA over bores.

Example: I have a 3.375" bore racing block that I want to put new pistons into. I looked up ring sizes and there are tons of 86 mm rings available. So, you divide 86 by 25.4 and you get the bore size in inches. The result is a 3.3858 bore . . . just .010 over my current bore. When I order pistons, it will be for 86mm rings. The block will NOT be bored until I have pistons in hand . . .