This is a A-PR149 Piston Rings PN: PR149Main Description As Following : A-PR149 Rings, Piston P.N: PR149 Overbore 4" To 4-1/8"4 Ring Kit.comp rings .091" thick; oil ring .2435" thick Crossed From: PRS120 , , PRS121 , , PRS164 , , PRS168 , Found in Section & Models : Engine Parts > C264 & C281 CID, Case-IH TRACTOR: W400 (C264 ENG SN 163808>), Case-IH TRACTOR: W450 (C281), Case-IH TRACTOR: 400 FARMALL (C264 ENG SN 163808>), Case-IH TRACTOR: 450 (C281), Engine Parts > C264 CID, Case-IH TRACTOR: SUPER M, Case-IH TRACTOR: SUPER MTA, Case-IH TRACTOR: SUPER W6, Case-IH TRACTOR: W400 (SN <163807), Case-IH TRACTOR: W6TA, Case-IH TRACTOR: 400 FARMALL (SN <163807), Engine Parts > 201 CID Gas, Allis-Chalmers TRACTOR: WC, Allis-Chalmers TRACTOR: WD, Allis-Chalmers TRACTOR: WF, Allis-Chalmers TRACTOR: W25, Engine Parts > 226 CID Gas, Allis-Chalmers TRACTOR: D17 (GAS), Allis-Chalmers TRACTOR: WD45, Allis-Chalmers TRACTOR: 170 (GAS), Allis-Chalmers TRACTOR: 175 (GAS) Associated Items : New Also A-AC-O-D17DERLY, A-AC-O-D17DSL, A-AC-O-D17GAS, A-AC-O-D17III, A-AC-O-D17IV, A-AC-O-D17MID, A-AC-O-IMPLHITCH, A-AC-O-MARKIVANDV, A-AC-P-D17, A-AC-P-D17SERIV, A-AC-S-D17, A-AC-S-FUELINJ, A-FRM-ACCACO, A-SMAC201, A-AC-C-WC1934, A-AC-C-1935, A-AC-O-WC, A-AC-P-WCWF, A-AC-S-WCWFRC, A-FRM-ACCACO And : Overbore 4" To 4-1/8" 4 Ring Kit. comp rings .091" thick; oil ring .2435" thick