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Caseys69
04-30-2019, 02:25 AM
A friend has a set of original pistons and we cannot seem to find anything on them. The number stamped on the top of the piston is 3875909
dvss1
04-30-2019, 03:04 AM
Are you sure thats the number? Could it be 3875905? 3875905 is first design hi perf 396 oversized piston. I looked at a set at the Jefferson swap meet over the weekend.
Caseys69
04-30-2019, 03:09 AM
I just posted a pic, its definitely a 9
dvss1
04-30-2019, 03:17 AM
Yes definitely a 9. I would measure the piston and see what the OD is. Looks like a 396 piston.
dvss1
04-30-2019, 03:20 AM
Are there any Numbers on the inside of the piston?
Caseys69
04-30-2019, 10:43 AM
Its just stamped TRW on the inside