[pooner9185]

I have recently aquired a chevy small block and I'm having trouble finding out exactly what it is. I have found Four numbers. 3970010 along with "hecho en mexico" on the back drivers side. 254 on the back passenger side. 010 on the drivers side in front of the oil filter. and the engine code is "MK01800." I have determined it is a replacement engine from mexico with %10 nickel (or tin?) added. It is either a 302, 327, or 350 and 2 or 4-bolt main (I have not removed the oil pan yet). I cannot find anything about the engine code since it seems to be in the wrong order, not the typical plant-date-suffix format. How can I determine what the displacement is for this engine (it's not casted that I can see) and what year it was made/assembled?

[lets cut it up]

I beleive a "010" block is a 350. I am not sure about the other numbers. I have heard that the mexican blocks are trouble though. Not sure exactly why though,Tim

[sam-missle]

you have a 350, back when the 302 and 327 blocks were built, mexico didn't know how to cast a block.

sam-missle

[JeffB]

This is interesting,I had a 350 block like that in the truck I had, only did a balance and blueprint ,L-79 Cam,Flat tops,mild port to match,and it ran strong no problems.Now if this was a Ford 302 the Mexican blocks are in demand and stronger,go figure

[junior stocker]

Like a lot of people, I too have one of these; it was a G.M. crate motor I bought new. At 15,000 miles it dropped an exhaust valve, ruined one head and punched a hole in the piston. Only thing I can say about a "hecho en Mexico" block, is that it appears the cast iron must be "soft", as there was quite a ridge in the cylinders at the top of the bore; a lot more ridge than I would expect on a 15,000 mile motor. I'm still going to reuse the block, only with a large journal 327 crank, good rods, and a set of NOS G.M. hi-perf 10.35:1 pistons (the ones everyone seems to refer to as 11.0 or 11.5:1 compression ratio pistons). I think I'm going to grind the "hecho en Mexico" letters off the block so no one knows it really is, in my opinion, a block casted with inferior cast iron. At least that way, I won't have to deal with the stigma from others about it being a lousy block.

[Twistedwrench]

I’ve built a couple of mills using hecho blocks and have had no troubles at all. Granted the they are both fairly mild and around the 350hp range. Just my experience with them.

[DoubleVision]

some years ago on here we had many discussions about these blocks. They are "target master" replacement engines from GM. To talk bad of them opened a can of worms with some. From what I had heard and read, they were soft, the cast iron was not the same quality and they wore very quickly. Others say they built them and ran them with high power and never had a single issue so I would say the debate is out. Some I would say are soft and the material used wasn`t that good, others I would say are fine to use, but it`s kind of hard to tell what you have cast iron wise by just a visual inspection and I`m not sure if there are any "hardness" testers for cast iron.
This is just my opinion on reading what many others have said of these blocks.

[cleve.Z]

I see I'm not the only one with questions and concerns about a block casted
anywhere else than the good old USA.
I have recently picked up a car that has a non-original 350 motor in it.
On the upper driver side rear block deck it has casted into it Hecto in Mexico. I tried to run the number to find out its origins but unfortunately the only thing that can be positively identified is that it is a 350 cubic inch, two
pc. main seal, and was made some time in the early to mid eighties.
The one thing that I clearly have noticed about this engine it is a little noiser that the motors from the late 60's and early 70's.
There is absolutely nothing wrong with the motor as everything has been check and inspected. But being around small block Chevy's my whole life I have never had a motor when it's running an from the underside you can the sound of internal components whirling around. Had a few other people familiar with small blocks take a listen and they said I was correct. Their thoughts where the noise was due to poor quality in the materials which were allowing sound to travel easier thru the block. If so what does this say for the strenght of the bock?

[DoubleVision]

This thread is 2 years old. Sorry to say I`ve never heard of what your saying. Not saying it`s not possible, but I`ve never heard of a engine being more noisy because of the material it`s made of. Park it next to a engine casted in the USA that`s worn out and it`ll be plenty noisy too.