Which 302 block is best ?

twosheds · Jan 13, 2010

I read sometime that I should not use the roller block 302 from 1981 to ?, as it was not as good or strong of a casting as other 302 blocks. Anyone know which is the best 302 block to use?

2+2GT · Jan 13, 2010

"Hecho en Mexico". No kidding.

Tanus · Jan 13, 2010

how much better is the mexican block? I think I heard it has a higher nickel content or something.

2+2GT · Jan 13, 2010

Hard to sya about the casting itself without some NDT, but they all had 289HP bearing caps.

Of course, these are available new.

shoguun · Jan 13, 2010

strongest is a boss 302. it has a 4 bolt main cap but otherwise hecho in mexico

D.Hearne · Jan 13, 2010

The best roller blocks are the 86-2001 castings. E6SE, E7TE, F1SE are the one's I've run across. There's another heavyweight like the Mex, but with the std main caps, this is the D8VE block. The 80-84 blocks are all lightweights. As is the 85 roller block.

twosheds · Jan 13, 2010

Many thanks. How do you identify the Mexico block ? Special markings or casting codes ?

shoguun · Jan 13, 2010

twosheds said:
Many thanks. How do you identify the Mexico block ? Special markings or casting codes ?

hecho in mexico lol. probably look up the vin number

Tanus · Jan 13, 2010

it says "hencho in mexico" on the lifter galley

ultrastang · Jan 15, 2010

Compared to a late-model 302 U.S. block, mid-'70s Mexican blocks have thicker main caps like those on a '65 289 block and are supposedly cast with a higher nickel content. According to various Ford sources, Mexican blocks do not have thicker cylinder walls than standard blocks.

Most non-Boss 302 block castings are good through about 450 hp. Beyond that level, I wouldn't go out of my way to find a rare Mexican block; instead, consider a truly superior casting, such as those available from Ford Racing, Dart, or World Products.

The words, "Hecho en Mexico" [Made In Mexico] is cast into the lifter valley [intake has to be off to see this], has thicker main caps than standard 302 block [oil pan has to be off to see this], and has a small roundish protrusion in the casting, on both sides of the block, sticking out the front just below the heads that regular production 302s don't have. You can see this just by looking at the front, outside of the block.

D1ZM-6015-AA

camachinist · Jan 15, 2010

I have a few pictures of an actual Mexican block for comparison. IME, absent endurance applications, a normal vintage 289/302 block is good for 450-500hp; obviously, that's an optimized situation, with everything being built to that level.

Front view

Crankcase front

Crankcase rear

Crankcase overview

If I was building a non-drag-racing track car today, I'd go with an aftermarket block. I'd only go to the aftermarket block for drag racing if it was targeted at the 2 hp/ci range. If a normal block lasts 100-150 drag racing runs before maintenance, to me, that's acceptable. IME, that's a whole season. The aftermarket block would need freshening at that point anyway, so the honing/teardown costs would be roughly similar and one can buy a half dozen (or more) OEM blocks used for what one aftermarket block costs. As OEM blocks become rarer (a fact of life these days) acquisition costs would begin to favor the aftermarket block. However, if the OP has a plentiful supply of OEM and the application isn't such where an aftermarket block is required, there ya go.

Optimized, a 1 - 1.2 hp/ci 302 will give most drivers on the street more than they can handle. An easy way to discover this is to WOT such an engine in low gear and attempt to turn.

rbohm · Jan 15, 2010

i agree with the others, unless you are going to make more than 400hp, any 302 block will do nicely.

twosheds · Jan 15, 2010

Thanks again Gentlemen, and awesome pics. I am building a daily driver and think I will stay in the 350 HP range. Would like to add fuel injection such as the FAST system. Wanted a stronger block than the 81-85 vintage in case some day I want to add a little more power. Sounds like the Mexican block is hard to find and expensive, thus I think I should stay with an 1986 or newer block.

Tim

Sicarius428 · Jan 15, 2010

The HO blocks are good to about 450 so unless you are serious about hitting that mark, A roller block will be just fine. Typically the HO blocks split down the middle from top down so all the stronger caps and girdles you put on it really won't help. HO blocks are plentiful and cheap. Again if you have plans for a serious beast, have you considered a 351? Not trying to throw a monkey wrench into your plans but just a thought since you are at the planning stage...
Kevin

D.Hearne · Jan 15, 2010

twosheds said:
Thanks again Gentlemen, and awesome pics. I am building a daily driver and think I will stay in the 350 HP range. Would like to add fuel injection such as the FAST system. Wanted a stronger block than the 81-85 vintage in case some day I want to add a little more power. Sounds like the Mexican block is hard to find and expensive, thus I think I should stay with an 1986 or newer block.

Tim

The D8VE block is just as hard to find, but as no one has yet realized their strengths, they can be picked up for pennies. The roller's selling point is cams and lifters are cheap and plentiful.

mrmustangman357 · Jan 15, 2010

just use a roller 5.0. mexican blocks are a little hard to come by and use flat tappet cams, which are known for their nagging issues with today's oils.

or go 351W and be done

Which 302 block is best ?

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