Anyone familiar with the Mexican 302 blocks? I know I've read some things about it but came up empty when I tried searching. I acquired a '71 302 to build for my F150 and discovered when I tore it down that it's definitely Mexican. The word "Mexico" cast into the top of the block is a pretty good clue... . It has a casting number D1ZM-6215-AA

Anyone know how they differ from the typical 302 block? I've heard they have more material in the main web area...is that correct? Are there dimension differences I should be aware of?

Any input appreciated!!

 

The main caps are thicker like the older 289 Hi-po blocks had. Good find.

 

take a bunch of pictures and send them to me......That would be awesome...........

I think the blocks have two humps on the front one on each side I think.....

 

Yes the main caps are bigger like the hipo 289 and it is said that they used a higher nickel content but that has never been proven from what I have read, it is always contested. And you should have one bump above the oil plug on the front of the drivers side. At least thats how my mexican block is.

 

Any idea what the deck height is supposed to be on these blocks? I haven't made an actual measurement on that yet, but I measured the piston/deck clearance at 0.046" and the compression height on the stock pistons at 1.600". Using the 60cc chamber cylinder heads I have with the pistons I had planned on using, that works out to a compression ratio slightly above 8:1. Not quite what I had in mind.

All my books show the '71 302 having a deck height of 8.206" which would give a piston/deck clearance more like 0.011"-0.016" and bump compression up closer to 9:1. Unless I'm overlooking something (quite possible) it looks like this Mexican block has a taller deck height than a "regular" 302. Anyone else run into this?

This engine will go into my daily-driver/get-me-to-work truck so I'm only looking for around 9:1 compression, but not too much less. Suppose anyone offers hypereutectic pistons, flat-tops w/eyebrows, for a 302, with a 1.603" compression height? What kind of combinations has anyone built using a Mexican block?

 

if it's been rebuild there is a chance someone put pistons that had a shorter comp heigth, speed pro makes them. They are every where I know I bought some and the slugs were to far down for my liking. I returned them and got the right ones 1.608....

best thing to do is mock it up with the rotating assy you are going to use, do all 4 corners and deck it accordingly...worth every penny.....

 

Wouldn't you want to index the crank before you deck the block to get the compression you want?