I have a good wrench 350 it has apx 10k on it and it was purchased in 99ish recently i was getting combustion gasses and pressure into the cooling system after i got the motor really really hot. so i pulled the heads to do the head gaskets and could not find the point were the gasket failed, the heads are straight. so i was told that the gm crate motors had issues with heads cracking if they say hecho in mexico was this guy yanking my chain or is their some fact to this. if so were do i look ? any advice. and i did read the chevy faqs and have googled and cant seem to find the answer Thanks for the help

Did you actually have the heads check to make sure that they weren't warped? Because a "blown head gasket" is not necessarily the gory, mangled mess that we envision in our heads when we traditionally think of a "blown head gasket".

Cause it doesn't have to warp much, a couple thousandths and steam and coolant can escape out the tail pipe. Or vice versa.

But yes, heads can crack. Blocks can crack as well. If not sure, you might want to have the block and heads both magnafluxed.

yes had them check out and they said they were fine i understand stuff happens like heads/block cracking but the way that it was said to me was like they had a major problem lots off blocks and heads cracking in the same spot due to a problem when they were made

Did you do a compression check to find out which cyl. was blown? If not you kind grasping at straws if you find nothing obivious. Did you see anything with the gaskets themself on teardown? If not you better have you block checked. Anytime a motor is run really hot someone can crack something head or block and alot of people do stupid things like that.:shaking:

Its kinda late now, but a comp test would have been helpful prior to teardown.

I guess at this point you could put new head gaskets on, and bolt it all back together and re run a compression test, and even see if its fixed.

Or, if you got the time and money to do it, take the block out and have it inspected.

Which is probably what i would do, cause I hate rework.

yes i ran a compression test before i tore it down #s 6 and 8 were low but i figured it out my block is cracked damn i got shitty luck thanks guys. was their problems with the quality of some good wrench blocks and heads made in mexico.

how did "I got the motor really really hot"
turn into:
"They have problems with quality"?

i realize i got it hot and when shit gets hot stuff breaks i could not find the problem and had heard that the quality of some of the blocks and heads was questionable i was trying to cover all the bases thanks for all the help everyone

when you get a motor really hot....the headgaskets blow:smokin:

toss some new gaskets in and forget the hearsay

when you get a motor really hot....the headgaskets blow:smokin:

toss some new gaskets in and forget the hearsay

if you read the posts he said the block is cracked, throwing head gaskets at it wont fix shit.

and yes those blocks and heads did have problems, just poorly cast for the most part and shit metal. had a set of heads crack on me, usually find them in and around the exhaust valve seats if its the heads.

if you read the posts he said the block is cracked, throwing head gaskets at it wont fix shit.


fuckit nevermind

These motors are ok for the money you spend. Now that you've got a problem. I would replace both the block, and the heads. If you step up to the crate motors with Vortec heads I'm pretty sure these are American cast motors.
Please correct me if I'm wrong.

I've heard just the opposite. That the Hecho en Mexico blocks and heads were based on the early thicker castings and for the most part were pretty good engines. I've installed a few for people and they have never had any problems with them.

Ive had several of the hencho in mexico engines and they ran really good. The castings were not the prettiest, but the machine work was excellent and they held together well even under a 100 shot with no problems.