Please forgive me if this has been discussed in another thread,
I have a 1970 429 "D0VE-A block. D0VE-C heads" from a 1970 Lincoln Continental that I am rebuilding for my 56. Pretty much just a stock rebuild with a mild cam.

Here's my issue: I had to have the block bored .030 over, no big deal, I ordered and received a set of Silv-O-Lite pistons (4.390") from Summit Racing which I give to the machinist and he says they're the wrong ones. When I asked why they were wrong he said they are for a newer 429. When I asked what's the difference? He just says "they won't work in a 68 to 73 block". I asked for one of my old pistons to compare and see what the differences were and he says he already trashed them.
So my question is, does anybody know what the difference in the pistons are between a 1970 D0VE-A block (1968 to 1973) and the later (1974 on) block?

Thank you in advance you your assistance

 

The later 429 is a truck engine. I think this came up before. I will try to search it out later.

 

Post 4 has the specifics on rod and piston length and compression height.

https://www.ford-trucks.com/forums/1...l#post18809532

You should have had the pistons in hand before the bore job so they could be sized right. Maybe the guy was planning on that and didn't finish the hone yet.

 

Early blocks from '68 to about 1971 have a shorter deck height. They are nominally 10.300. Later engines have a deck height that's about .020 higher at 10.320 nominal and maybe that's what he's talking about. Rebuilder pistons will usually be made with a compression height that's about .020 shorter to allow for blocks that have been decked so it is most likely that your pistons will fit and work fine.

There are no "car" 429's after 1973. With those engines you have to be very careful with the compression. All of the engines with the DOVE style heads are high compression by today's standards so be sure to keep that in mind when you select your pistons.

 

Thank you, This was the info I needed.

 

I built the 460 in my '79 pickup using a 1969 block. With a KB-138 piston it is a little bit plus on the deck clearance. I can't remember how much but I think about .003. It has been ok with a .043 gasket but it never gets revved very high. I think I turned it to 5500 when I ran it on the dyno back when I originally built it 20 years ago. Those pistons have a 1.772 compression height.