Reply to "How long to stroke a 9.2 deck block?"

Stroking a stock 351-C block over about 3.75" is a swamp you may not want to enter without professional help. Those 408s all use a piston that has the wristpin hole going right through the oil control ring groove. A support rail is supposed to go under the oil control ring to keep it from sagging; sags shorten the ring which leaves a space for oil to not be removed on the downstroke and oil use skyrockets. In addition, ALL piston rings rotate in use and when the oil ring ends reach the huge wristpin access holes, they stop and the sharp ring-ends bend, then begin scoring the bores. We had one 408 that was home-built with parts sourced from all over. The builder wasn't familiar with oil ring supports so he left them out. The engine was strong but used a qt of oil every 150 miles from new. A new owner finally pulled the engine and had it pro-rebuilt after 3000 unsatisfactory miles.

A second one had a different support-ring problem. The thin flat support ring has a dimple that matches a depression machined in the oil control ring groove bottom. Some use a tiny roll pin. This is supposed to keep the split support ring from rotating. But it only works if the support ring is installed right-side-up. This one wasn't done right in all 8 bores. Again, some support rings rotated, the ring ends got stuck in the wristpin access hole and stopped, then began scoring the bores. That one is now being pro-rebuilt, too. Both were new-owner Panteras in the Reno-Tahoe chapter of POCA.

Other things sometimes happen when a con-rod is chosen. If the rod chosen isn't long enough, the crank throws will hit the BOTTOM of the pistons on the downstroke. If the rod is too long, the piston tops hit the head. And with some combinations of parts, the front crank throw will hit the Ford oil pump that overhangs it. Cutting the crank for clearance unbalances the assembly, and on and on.... And we haven't even addressed cam problems.

Buying an engineered rotating assembly for a home-assembled motor might not be a guarantee of no problems, either. 45-yr-old blocks normally need squaring up in a surfacing machine which shortens the cylinder lengths, sometimes causing interferences between pistons and the heads. And I wouldn't spend a dime on reworking a stock block without a sonic check of the cylinder walls. I suggest getting a complete assembled short-block from an experienced builder to avoid such problems. The money saved going other ways is often non-existent by the time the bugs are fixed. Good luck, anyway.