427 Stroker Engine Block Coolant Drain Plugs

[gbranham]

For those who have built a 427 Boss stroker, can you tell me what part number you used to plug these ports on either side of the block? I've Googled for hours, and some suggest 3/8 NPT, but I have a couple of 7/16‐20 plugs that thread in nicely. However, I don't like how the bolt head seats on the block. I'm looking for an actual Ford part number. My next call is to Ford for support, but thought I'd ask here first.

[rich grsc]

It's 3/8 NPT, pipe thread

[gbranham]

I talked to Ford Performance tech today (Ken), and he was a great help. He was really surprised those plugs are missing; he alleges their 3rd party builders should be installing those in short blocks. I sent him pics, my proof of short block purchase, and the aluminum serial number plate on the block, and he's sending me the plugs free of charge. He said they've had a recent change in that plug (my block was built 4/11/24), so he's sending me the right part. I didn't rattle off the size, but I thought he said it was an ORB , 9/16-18 something or other.

Anyway, if anyone encounters this, he asked that they reach out to Ford tech, and ask for Ken for assistance. They're keen to know if they have a QC issue.

[gbranham]

This has been a real head-scratcher. Ford sent me these 9/16-18 plugs. They're too big. I called Ken at Ford Performance back, and he's confused, as well, as his parts system tells him that's the right plug. He's going to check out some short blocks in the warehouse Monday or Tuesday and get back to me. I also tried a 3/8 NPT plug; too big. 1/8 NPT is too small. The only thing I've got to fit properly is a 7/16-20 bolt from the coffee can. Weird. He believes these shoud've been installed with all the other plugs when the short block was assembled, so he's really curious if they have a QC issue. I did find some of the Zero-Leak Gold plugs on eBay in 7/16-20 size (AF 22S-S04 - #4 Zero Leak Plug(ORB Thread) (7/16''-20 Threads) | eBay (https://www.ebay.com/itm/172512795520?var=0&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338590836&toolid=10044&customid=c78c6a7dbc4511e353b50c0aaac78be8)), but I'll wait to hear from Ford. He sent me the 9/16-18 free of charge, so if he can sort it out, I'm sure he'll send me another pair on the house. Not that they're expensive, but it's just a weird deal.

200861

[rich grsc]

Never seen that used before

[gbranham]

Never seen that used before

I've never seen them, either, but my short block has probably a dozen of them installed in various places.