factory 383/440 big-block valve covers 1970-'71 changeover dates

[6bblgt]

I believe there are at least 3 different RH (passenger side) valve covers that were used on big blocks for the 1970 & 1971 model years

RH - passenger side

A * narrow oil fill & no "divot"
B * narrow oil fill & "divot"
C * wide oil fill & "divot"

trying to determine when the changes took place

who has a late '70 or early '71 model year big block car (B, C, E-body & 383 or 440) with it's original valve covers: that can share their car's valve cover style, scheduled production date, engine assembly date and assembly plant info?

[Chryco Psycho]

Cannot help you , mine had the original covers still but not the original engine 

[6bblgt]

"A" - August 1969 thru May 1970 production
"B" - June 1970 thru November 1970 production
"C" - December 1970 thru July 1971 production

anyone have dates to confirm or contradict the above?

[6bblgt]

& the LH (driver's side) there are only 2, correct?

did the change occur at the end of '70 model year or during '71 production?? 

if anyone can share their original valve cover style & the car's SPD (scheduled production date)  & EAD (engine assembly date)   

[70 Challenger Lover]

I always understood the bracket on the top to be the 2 barrel 383 cars.

[6bblgt]

I always understood the bracket on the top to be the 2 barrel 383 cars.

the bracket is for the #7 plug wire on all big block C-bodies (1970-'71)

all 383-2bbl B & E-bodies use the same LH exhaust manifold as 383 4bbl, 383HP, 440HP & 440 6bbl (valve covers are the same)