Re: [AMC-list] Best years of 258 parts for Strokers

[Frank Swygert <farna@xxxxxxx>]

Wrong on the pistons. All the rods are the same. The difference in compression ratios over the years are from the dish in the pistons and changes in the combustion chamber of the head. 

My answer posted on the Strokers group (you didn't mention pistons there):

It really depends! Mid 1980 and later 258 cranks have four 
counterweights and are substantially lighter than older ones, I seem to 
recall about 40 pounds lighter. If you want an engine that will turn up 
quick that's the one to use. I'd prefer it for a street engine. The 
heavier pre mid 80 crank has eight counterweights and is claimed by some 
to be easier to balance and of course is a good bit stronger than the 
later one. No one has complained about breaking either, so there is no 
reason to assume the late crank is that much weaker than the early one. 
There is a bit more flywheel effect with the heavier rotating mass, 
making it a bit harder to stall at low rpm. For a rock crawler it's 
perfect! So what are you thinking about building? Race/street engine 
that need to turn up quick -- lighter crank. Rock crawler -- heavy crank.


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Date: Thu, 25 Mar 2010 00:34:42 -0700 (PDT)
From: Jesse <j2sax@xxxxxxxxx>

I am going to post this on the Strokers Group as well.  

What are the best years of 258 parts to use for strokers?  I am getting ready to get rid of a BUNCH of engines (I have 18 in my shop) but am keeping the 4.0's and relevant 258 rotating assemblies, a couple of 360's and 401's.  

I believe it was wrist pin location that was slightly different which gave a lower C.R..  

--
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
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