The Best Gasket seal is available on Ebay for a MUCH better price. Eliminate the middleman and the outrageous markup!
www.ebay.com/itm/226010441522?Check the fit of the seal by pinching a 1/2" wide strip of copier paper between the bottom of the seal and the crankshaft hub as you install the rear main cap. With the bolts snug, but not yet torqued, there should be a firm drag on the paper as you pull it out. If it slides freely, add shims between the seal and the block and the main cap. It looks like Jon beat me to the seal shimming suggestion!
Jerry