throttle body plate:throttle body plates are designed to replace the factory plates using existing bolt holes, doing this can it hurt my engine 4.3L ?

 

need more info. year and is it TBI or injected? even the injected ones have whats called a throttle blade that controls air flow. if you can, put a picture of what you are talking about to help give us a better idea. you can use the button with a the little mountain on it and paste the internet address in that and it will do the rest for you.

 

4.3 L (262 cu in) Vortec 4300 L35 V6, SCFI, 190 hp (142 kW)/250 lb·ft (339 N·m) (VIN W)[7] 4wheel drive 4-door and can i descreened the M.A.f. sensor

 

Just leave both parts the way they are. It will be best for you.