Pulled the motor from a buddy's newly purchased 69 F-100.

The motor was siezed so we pulled the heads and oil pan to check it out. Here is what we found.

The bore is 4.125. I can't tell what the stroke is since none of the pistons are at bottom center. Are there any markings on the block to tell me what we have? I see that only the 406 and 428 have a bore of 4.13 and everything else seems to be a 4.00 or 4.05. I measured 5 cylinders and came up with 4.125 (carbon is probably the other .005).

This was reputed as a 352 with "good" 390 heads. The heads are common castings, but I suspect the block is something else.

 

The only way to be sure is to find the casting numbers on the block..

 

Where do I locate them? What am I looking for? I haven't dealt with an FE in a while.

 

Casting numbers in some cases will tell you what the block is. And in some not. The casting number is located on the right (pass) side of the block. Some blocks don't have a casting number and others carry a generic number used on lots of different bore blocks. I'd also get the date code and it's below the oil filter adapter pad. Or above it if it's a 63 or earlier block. If there are vertical ribs on the side of the block see fo there are 2 dots under the first number in the date code. Date code will be a number/letter/number(s) marking ex...4J25 or 3B5. By the sounds of it you have a 406 or 428 block. Get the casting numbers and date codes off the heads and intake too. That will help piece the puzzle together. Look for any marking on the crank like 2U, 3U, IU, IUB or a full casting number. Post what you find.

G.

 

4.125 = either a 360 or 390 that's punched .060 oversize. Remote possibility it's a .060 over 410.

 

Ahh right you are and I was not reading that right. LOL

 

Sorry Baddad. You mean .075 over std bore! Stock is 4.05 - 4.125 is .075.

 

Need to find out what crank you have in it. You can pull the pan or use a wooden dowel and measure through the spark plug hole!

 

Yeah, I though 4.05 + .060 = 4.11............... but then maybe the new math is different.

 

I was thinking with bore wear, a .060 over could mic out at 4.125. Now that I thought about it, a 4.13 with carbon buildup above the ring area could mic at 4.125"

 

That would be a hell of a lot of piston slap.

 

.015" bore wear is nothing, I've seen worse that were still running that needed a .040 over bore or better to clean up.

 

Got that bad boy cleaned up and measured this past weekend.

4.13 bore with a 3.78 stroke. We have ourselves a home made 410 (69 year model block).

Thanks for all the help guys.

 

That is not a 410, a 410 has the 4.05 bore, you have a 428.

Measure the pistons across the wrist pins.

 

The 410 and the 428 both have a 3.98" stroke, the difference is bore at 4.05(410) and 4.13(428). It sounds like a 406 to me.