okay i read the article about m block performance and paid close attention to the pistons. Hot rod says there are no perf pistons available, but obviously TMI. has had some made. BUT,........ You had to know it was coming! The article in our own articles section of this forum says you can use cleveland pistons, so long as you put the 400 crank in your 351m. I for the life of me cannot come up with a good reason to rebuild an m without adding the 400 crank. My own mblock in my 80 2504x4 will be upgraded to a 400. Afterall if you are going to buy a crank and our blocks dont care which one is in it, you may as well go for the cubes. Do they no longer make C pistons? Oh by the way i spent the weekend reading the 335 forums and absorbed alot of your builds and opinions,etc. I cant remember the name but one guy even proudly announced he could pull 17mpg highway!!!!! I would love to hear the rest of the story with that truck, sounds like he got it right. I'll be calling TMI tommorrow, but will also be looking for C pistons. Anybody know the size of the chamber with my 80, 351m 2v heads. much appreciated. Lets see how many guys kick me now. Thanks, Dan

 

the chamber size is 77cc. if my math is right my 9-1 cleveland pistons will give me right at 10-1 w/ t 400 stroke

 

don't forget that to use Cleveland pistons you have to add the expense of either bushing the rods to Cleveland size or honing the wrist pin bores to M/400 size, if the pistons will tolerate it.

 

With open chamber heads you don't want to go over 9:1 compression unless you use a big cam.

(TMI) has the pistons made for the 400 and can have them machined for any specialized application or heads.

Tell him I sent you!

 

Thanks guys, yea i forgot to mention the wrist pins but remembered that i would need to do it. Eric you are just helping an awful lot. I'm going to check my trans this weekend. I tried to call TMI and will have to just keep trying, until i get a body on the phone. Oh well I've got time. On that cam , I'm looking for somewhere between 9/10-1 on my motor and was looking at the other threads on the cams. Looks like it is one of the 2 smaller comps. The small one seems to be the one for the low speed grunt work, and the middle appears to be the ticket for dragging my hot rod around, Yes????? Which case I will have to try and decide which i will do more often, sound about right? Thanks, dan

 

Sounds good. Check your dynamic compression ratio. Check the links in my sig for more useful information.