KIT-MUFFLER 4870694 - Caterpillar

Improved Camshafts
Exhaust and intake camshaft lobe profiles were improved by increasing the width of the lobes. This improvement provides a more uniform surface profile across width of the lobe.Note: Some remanufactured camshafts with a former Reman part number may still utilize former design dimensions, and will not have a wider lobe. Improvements have already been introduced to achieve the same uniform profile as compared to new part numbers.
Table 11
New Part Number Former Part Number New Reman Part Number Former Reman Part Number
421-0049(1) 301-7454 20R-1893 10R-6393
421-0071(2) 301-7457 20R-1894 10R-6394
421-0087(1) 301-7455 20R-1895 10R-6395
421-0097(2) 301-7456 20R-1896 10R-6396
421-0155(1) 375-8958 20R-2927 N/A
421-0176(2) 375-8959 20R-2928 N/A
421-0189(1) 375-8960 20R-2929 N/A
421-0200(2) 375-8961 20R-2930 N/A
420-0455(1) 375-8956 20R-2931 N/A
420-0456(2) 375-8957 20R-2932 N/A
(1) Right bank
(2) Left bankThe change is effective at the factory with engine build date of 02 January 2013.The change is effective with Reman engines built on or after 02 January 2013.