trw 258 slug identified

[adh@xxxxxxxxxxxxxxxxx (Sandwich Maker)]

went over to my friend's engine shop and scanned his big '73-'91 trw
book

the 3000 series is, as i recalled, cast.  forgings are in the 2000
series.

to wit, all 3.750" bore, 0.931" wristpin:
L3000F	'steel strut'	1.581" ch	flattop			[199]
L3101F	'braced'	1.581" ch	.118" cup		232/258 to '76
L3102F	'steel strut'	1.581" ch	.134" dish		232/258 '77-9
L3104F	'steel strut	1.581" ch	.140" valve reliefs	304
L3103F	'steel strut'	1.633" ch	.158" dish		258 '80-'90
L2340F	'powerforged'	1.598" ch	flattop			[290]
L2341F	'powerforged'	1.598" ch	.108" cup		?
L2360F	'powerforged'	1.598" ch	.127" cup		?
L2480F	'powerforged'	1.598" ch	.140" cup		?

so the 3103 is an '80s stock replacement cast 258 piston.

and yes, that's what the 3104 description maps out to.  maybe they
mean .140" cup with valve reliefs as well?  i thought no 304 slugs
were flattops, though the hi-comp 290s were.

and btw the cups above are flat bottomed; dishes are concave.
________________________________________________________________________
Andrew Hay                                  the genius nature
internet rambler                            is to see what all have seen

adh@xxxxxxxxxxxxxxxxx                       and think what none thought