Quote:
Originally Posted by coreybrenner
On another note, I'm thinking of stroking the 389 in the parts car to a 421, but would like to use later model heads because of their superior combustion chambers. Is there a piston which will work with the later-model valve angles (but not be the 8-eyebrow weirdo-cut ones)?
I'm thinking of running propane in the finished product, so high compression isn't a big downer.
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Standard bore 428 pistons will be what you want. The valve reliefs will be in the right place for the later model 14-degree valve angle heads, the 389/421 originally used 20-degree heads.
I have been shopping around for affordable 421 pistons myself, the one that catches my eye is the $465 Probe SRS 428 Flat Top piston set which can be had in +.005" oversize (4.125"), you can see it listed here on the PPR site:
http://pacificperformanceracing.com/...-bearings.html
This +.005" 428 size will require boring your 389 block +.0625" over the stock 4.0625 bore size. In comparison just about any off the shelf 428 piston you'll find is +.030 (4.150") and is going to require boring your 389 block +.0875 over.
Of course you can order Ross pistons in any bore size and top configuration you like (dome, flat top, dished) for around $700 a set.