Technical 221 Pistons for 4" Stroke

Why can I not find these? Have an original bore 221 that has been pressure tested. Plan to bore over just enough to clean it up. Have a couple good 4" Merc cranks and 8BA rods and bearings for both.
I know it's not as popular and have heard the "why not just.... bigger, bigger..." but I like this block for the lightweight cars I'm building. I do have other 59, 59AB, and 8BA blocks but want to use this if possible. However, if I'm left buying Ross custom forged $750 pistons to get something less than 3.1875" then I'm just out for this build.
Ideas?
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I'm no expert, but isn't there a problem with 8BA rods not fitting through the smaller bore?

 

Yeah, I thought I heard that was not going to fit. Never tried it myself.

 

Yes, I don't believe the 8BA rods will fit through the small 221 bore. I've never built a 221, so you should check to see if this is true.

If so, then in order to use that crank, you'll need to have it reworked for the smaller journals (1.999") and then you'll need to run the early 91A or 21A rods and full-floater bearings.

If it was mine, I'd have the crankshaft offset ground to 4 1/8" stroke . . . isn't any more work for the crank grinder than just grinding the journals on-center to 1.999".

I'm not sure if Ross will make the smaller 221 pistons with a compression height for 4 1/8" stroke. You'll need to talk to them first. I would call "Ed" in the sales department - he has helped me many times!

If it was mine, I'd check with Ross first, then have the crankshaft work done, then accurately measure the true compression height you need to put the piston edge flush with the deck. The only way to know the exact number is to mock-up the engine with the crankshaft, two rods and two piston pins. You need to measure both sides of the engine to determine the best compression height to specify to Ross.

Also, change the rear main seal plates to the later ones that use a rope seal - as that is what the Merc crank will need. You can get the two pot-metal pieces from VanPelt or ThirdGen (at least I think so).

 

It's kinda possible.
Clark (@Enbloc) has done it a few times... Populate the piston with rings, push it down the bore far enough that you can then then fit the rod from below.

https://forum.retro-rides.org/post/2724571/thread

Another trick is to use the shorter French rods which allow you to use stock Ford pistons with the 4" crank.

 

Lot's of information here but I'd also ask your question over on the Ford Barn. Lots of Flathead guys on there.

 

Good stuff. Thank you all.
Indeed, I was intending to install the rods from underneath. I have plenty of the other parts like pot metal rope seal shells, etc.
The French rod trick I had never heard.
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It's what I have planned for my 99T block using some 45 thou over Ford pistons that a friend has in stock.

 

So 4" crank and 3.75" stroke bore pistons with the French rods even out on deck height?
What else would be needed?
Are French rods expensive?
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so I’m informed. Not put it together yet to be sure. My rods were free which helped with the decision making.

 

I guess so. That's great! Appears from searching that the french 6 7/8" rods are as difficult to find as the smaller pistons for a stroker. Looks like this will go back to a stock 3.75" stroke. I have others to more easily use the Merc cranks on.
Thanks for all the help and great ideas!
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