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

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?

I will post a picture of the other side when I get a chance. This 71 383 HP SPD B18 has the raised round area on the front of the driver side valve cover. Early 71 383 & 440 HP engines have the flat cover like a 70. 2 different covers were used on the drivers side also!

Dan,
I was thinking of talking with you about a post like this.
Thanks for posting.
This right side valve cover is from an untouched 70 Challenger 440-4bbl SPD B20 Nov 20th.
No indent in front
Did they add the indent because of the heater hoses?

IMO the additional "BUMPS" & "divots" were to cut costs in the manufacturing process

the majority of 1970 covers "A" are what's needed - 2 different valve cover stampings
the first change "B" included the power brake booster "divot" on both sides
the second change "C" included 2 large "BUMPS" on each side

now the stamping was the same for both sides: piercings for holes & welding of shields/tabs/brackets made them side (and/or engine/body) specific

Dan, now that makes sense. They use the same stamping for both sides saving time & money.
Thanks Bob

What would be the actual timeline generally accepted for covers A-C???

Also when did the outer studs instead of bolts end? 1969? Part of 1970? I've never owned a 70 with them but other's have.
Ron

that's the whole point of the thread - I'll take a stab at it (looking for confirmation & contradiction)

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



valve covers with 4-bolts & 2-studs were used until about the middle of 1971 production, let's call the introduction of 6-bolts at January 1971

here is a junkyard Imperial 440 3/30/71 - SPD

version "C" valve covers & 6-bolts

My original (440+6) St. Louis 71 runner with a SPD of first week December 70 has style B. I haven't had a chance to look at the engine assembly date yet.

440 valve covers 10/69 built LA Cuda. 9/25 engine assembly date stamped on top boss. this is a great detail discussion. keep in mind this is when I first got the car 11 years ago. the engine had a spray bomb job on the when I got it the car. I am also showing the driver side if anyone cares as well. sorry for the mess under the hood, I was in the disassemble/document phase at this point in 2008.

did not realize you could get a HP440 4speed w/AC. learn something new everyday

Hi Mike, I just added bbl to my post. It should read 440-4bbl. The SPD means schedule production date B20 . Sorry for the confusion.
Bob

no worries. in the end its all trivial nonsense. LOL

anyone with a late '70 June/July big-block car that can share what their original valve covers looked like?