Difficulties in parts search?

Parts list

Difficulties in parts search?

	Description	OEM Part #	Price
1	1 850838T01 New Genuine Part	850838T01	US $39.10
2	2 850839T01 New Genuine Part	850839T01	US $42.45
3	3 822647001 Seal, intake - black, valve stem	822647001	US $8.40
4	4 822647002 Seal, exhaust - green, valve stem	822647002	US $8.08
5	5 803554005 Spring, valve	803554005	US $10.78
6	6 855959001 New Genuine Part	855959001	US $2.90
7	7 822650001 New Genuine Part	822650001	US $9.50
8	8 803556 Keeper, valve	803556	—
9	9 850841002 New Genuine Part	850841002	US $20
	replacement
9	9 8M0081793 ROCKER ARM	8M0081793	US $20
10	10 825046001 Screw, adjusting	825046001	US $6.50
11	11 826150001 Nut, adjusting	826150001	US $3.71
12	12 850842001 Shaft-rocker arm	850842001	US $31.01
13	13 825452001 Spring	825452001	US $6.72
14	14 895118001 Washer	895118001	US $2.54
NI	NI 895188T04 New Genuine Part [0R139508] & Below	895188T04	US $3,771.42
	replacement
NI	NI 8M0046065 Powerhead Assembly [0R139508] & Below	8M0046065	—
NI	NI 895188T06 New Genuine Part [0R139509] THRU [0R310614]	895188T06	US $3,771.42
	replacement
NI	NI 8M0046065 Powerhead Assembly [0R139509] THRU [0R310614]	8M0046065	—
NI	NI 8M0046065 Powerhead Assembly [0R310615] & Up	8M0046065	—
NI	NI 835430T06 Cylinder Head Assembly Complete [0R139508] & Below	835430T06	US $1,191.79
	replacement
NI	NI 835430T07 Cylinder Head Assembly Complete [0R139508] & Below	835430T07	US $1,191.79
NI	NI 835430T07 Cylinder Head Assembly Complete [0R139509] & Up	835430T07	US $1,191.79

Intake And Exhaust Valves Diagram Mercury-Mercruiser F8 18232460-945637