I bought a used 351M that has already been bored .060 over. According the date on one of the bearings from the main journal it was rebuild in 1997. I have done some searching and have learned it is a bad idea to bore .060. My question is " since this engine has been already running for several years do you think it would be safe to refresh it and put it back on the road?". It has been unused since 2001. I pulled the heads and the cylinder walls look good. I was thinking of slipping in new rod and main bearings while it's on the stand. I have heard that on a small block chev that it's a bad idea to put in new rod bearings unless they are resized because the big ends sometimes get out of round. Is this a problem with 351M rods? thanks Jeff

 

I have not witnessed any problems with a .060 "335" series block yet, to install new bearings and rings would not be a big deal.

If you wanted to get technical, very few rods, if you checked them would be in spec. But people install new bearings all the time with no problems.

 

these motors are so available for sooo cheap I'm not sure i'd waste my time with 060 block- some folks have had problems and the common perception is to have it sonic tested...so whY? then...why not? time is your issue.

 

the 335 series engine are a thin wall design and should not be overbored more than .040.

 

All modern castings are thinwall design. Some suffered more issues than others like casting shift, etc. I've never heard of .060 over causing problems on a 351M/400 block.

 

i bored 289,s .060 years ago without a problem.you hear the warnings all the time but i dont thing one in a hundred gives a problem.

 

If the old bearings look decent, a new set of bearings the same size should be OK.

Why don't you slip a new crank and pistons in it as well? Make it a 400.

 

This block was bought to replace my original engine which I know is all stock( not bored ). Since my replacement block is bored .060 over ( which I did not know of this when I bought it) I think I am just going to bearing, ring it, and install a new cam. Since it's .060 over I fear if I stroke it to a 400 I may have some overheating issues. Later on I may turn my original block into a 400. Thanks for all your input and have a Merry Christmas. Jeff