[RobMcQuarie]

Dwight,
We have used these on some of our customers circle track engines and they have worked very well in higher rpm usage. The Ford/Federal Mogul spacer inserts are only rough sized and do need to be finish sized in the block. They are not a simple bolt-in. They should be installed by a competent machine shop. We line hone or bore ALL our performance blocks as a matter of course to ensure true bores, so we see installing one of these kits as just an additional step in the block prep. With main studs, or better yet, we use a billet steel main cap girdle w/studs, to strengthen up the mains, you will have a very tough bottom end able to handle some decent rpm's.

I believe the main cap girdles to be very important. I have seen numerous non-girdled Ford blocks used for racing/hot street that have exhibited extensive cap walk, while the girdled blocks don't. I also recommend them for street driven strokers due to the increased power outputs and higher stress levels. We supply a MCGirdle on all of our customers stroker builds.

There are two different width spacers, depending on the thrust width type crank you are going to use, so make sure you match them up to the type crank you are planning to use.
Rob