[RamAirJohn]

PONTIAC HOOD TACH INFO:

1) Pontiac produced (2) basic Hood Tachs;
1st Style (tall case; 3.00") entered production in Feb/Mar '67 This was used until supplies were exhausted up until sometime in Jan. '68 on Firebirds. The 2nd Style was the shorter case (2.25") which remained unchanged until it was last used on the '72 model cars.

2) 1st Style Hood Tachs used (1) bulb; 2nd Style-(2)(No. 168 is the bulb type/size). Bulb socket is identical to that used on
'70-'72 Tempest tailights (and others).

3) Hood Tach Assy Part Numbers:
67-68 F/6 6468670 (6500 redline)
67 F/8 6468675
67 T/6 6468436
67 P/8, T/8 6468410
68 F/6, T/6 6468956 (5500 redline)
68 F/8, T/8, P/8 6468972
69 F/8, T/8, GP-8 6469694
69 F/6, F/8 6469689
68-72 All V/8 5657097

4) 1st Style Face colors for Firebird: green on black. A & B bodies: white on steel blue background. 2nd Style: white on steel blue ('68 only) '69 - '72 used white on black.

5) 1st Style had "RPM X100" on face w/blank 'tab' over needle pivot. 2nd Style had "RPM" on 'tab' over needle pivot. Both styles had "PONTIAC" on face.

6) 1st Style OHC tach was 6500 redline. This was changed to 5500 near end of April 1967 (for '68 models). Some early '68s may have used left-over
'67 units. 1st Style V-8 redline was 5200 redline (approx). The 5500 redline did not appear on the 1st Style (tall) OHC Hood Tachs. This change took place in the early part of production for '68 model year cars on the 2nd Style (short) Tach. Obviously, since most '68 Firebirds built
up into Jan.'68 used this 'Tall' Hood Tach, many still had a 6500 redline. For some reason, the early '68 GTOs received the 2nd style (short) Hood Tach before the early '68 Firebirds.

7) 2nd Style face started out as a 'circular' pattern for the RPM indicator graphics. This changed to an easier to read 'oval' design two months later (June '67) although examples of the circular face have been found in cars with build dates into Nov. '67. Redline color was Red until mid-way through 1970 when it was changed to a
fluorescent Orange as it remained till the end ('72).

8) 2nd Style, circular & oval face pattern used (2) different redlines:
5100 and 5500. There is speculation that RAII used the 6Cyl 5500 redline however,
no part books support this. All others used 5100 redline.

9) Rarest of all Hood Tachs would have to be the prototype version planned for the RAV application. This had a shift indicator light display at the bottom. Only known one is on a '69 Judge RAV built by "Purely PMD" (1980s).

10) '70-'72 Hood Tachs included a hose/filter to eliminate condensation. All Hood Tachs included a rivet in addition to the (4) studs/nuts (anti-theft).

11) Reproduction Hood Tachs have improved significantly since they first appeared almost 20yrs ago. Improvements have been made with regard to lighting, circuitry and sealing to keep moisture out. Some faces are of a translucent plastic while others have silk-screened, metal faces (or adhesive applied vinyl overlay).
Some cheaper versions have the face trim molded as one-piece. Edges at face are somewhat 'softer' (rounded) than originals.

12) GM also produced a Hood Tach for the early ('70-'72) Buick GSX. This is essentially the same Tach except for "BUICK" on the face. Additionally, there was a 'generic' Hood Tach produced by GM with the "AC/DELCO" name on
the face (used by Yenko & Motion). AMC also used a variant of the AC/Delco style.
An aftermarket "DIXCO" Hood Tach was made in the 60s/70s (with "DIXCO" on face). This case differs from the GM unit. These were also used on some Mustangs & MoPars(dealer accessory).

13) There are several well-known authorities who restore original Hood Tachs to include
re-silk screening the original face, new circuit board, rebuilt or new movement (head) and
case/trim repair/replacement This would be for the concours types as prices can exceed the
$250 or so for a new repro unit.

NOTE:
IF YOU HAVE CORRECTIONS TO THIS INFO, PLEASE LET ME KNOW. THANKS.

John
RamAir@comcast.net
Eph. 4:32

[RamAirJohn]

PONTIAC HOOD TACH INFO:

1) Pontiac produced (2) basic Hood Tachs;
1st Style (tall case; 3.00") entered production in Feb/Mar '67 This was used until supplies were exhausted up until sometime in Jan. '68 on Firebirds. The 2nd Style was the shorter case (2.25") which remained unchanged until it was last used on the '72 model cars.

2) 1st Style Hood Tachs used (1) bulb; 2nd Style-(2)(No. 168 is the bulb type/size). Bulb socket is identical to that used on
'70-'72 Tempest tailights (and others).

3) Hood Tach Assy Part Numbers:
67-68 F/6 6468670 (6500 redline)
67 F/8 6468675
67 T/6 6468436
67 P/8, T/8 6468410
68 F/6, T/6 6468956 (5500 redline)
68 F/8, T/8, P/8 6468972
69 F/8, T/8, GP-8 6469694
69 F/6, F/8 6469689
68-72 All V/8 5657097

4) 1st Style Face colors for Firebird: green on black. A & B bodies: white on steel blue background. 2nd Style: white on steel blue ('68 only) '69 - '72 used white on black.

5) 1st Style had "RPM X100" on face w/blank 'tab' over needle pivot. 2nd Style had "RPM" on 'tab' over needle pivot. Both styles had "PONTIAC" on face.

6) 1st Style OHC tach was 6500 redline. This was changed to 5500 near end of April 1967 (for '68 models). Some early '68s may have used left-over
'67 units. 1st Style V-8 redline was 5200 redline (approx). The 5500 redline did not appear on the 1st Style (tall) OHC Hood Tachs. This change took place in the early part of production for '68 model year cars on the 2nd Style (short) Tach. Obviously, since most '68 Firebirds built
up into Jan.'68 used this 'Tall' Hood Tach, many still had a 6500 redline. For some reason, the early '68 GTOs received the 2nd style (short) Hood Tach before the early '68 Firebirds.

7) 2nd Style face started out as a 'circular' pattern for the RPM indicator graphics. This changed to an easier to read 'oval' design two months later (June '67) although examples of the circular face have been found in cars with build dates into Nov. '67. Redline color was Red until mid-way through 1970 when it was changed to a
fluorescent Orange as it remained till the end ('72).

8) 2nd Style, circular & oval face pattern used (2) different redlines:
5100 and 5500. There is speculation that RAII used the 6Cyl 5500 redline however,
no part books support this. All others used 5100 redline.

9) Rarest of all Hood Tachs would have to be the prototype version planned for the RAV application. This had a shift indicator light display at the bottom. Only known one is on a '69 Judge RAV built by "Purely PMD" (1980s).

10) '70-'72 Hood Tachs included a hose/filter to eliminate condensation. All Hood Tachs included a rivet in addition to the (4) studs/nuts (anti-theft).

11) Reproduction Hood Tachs have improved significantly since they first appeared almost 20yrs ago. Improvements have been made with regard to lighting, circuitry and sealing to keep moisture out. Some faces are of a translucent plastic while others have silk-screened, metal faces (or adhesive applied vinyl overlay).
Some cheaper versions have the face trim molded as one-piece. Edges at face are somewhat 'softer' (rounded) than originals.

12) GM also produced a Hood Tach for the early ('70-'72) Buick GSX. This is essentially the same Tach except for "BUICK" on the face. Additionally, there was a 'generic' Hood Tach produced by GM with the "AC/DELCO" name on
the face (used by Yenko & Motion). AMC also used a variant of the AC/Delco style.
An aftermarket "DIXCO" Hood Tach was made in the 60s/70s (with "DIXCO" on face). This case differs from the GM unit. These were also used on some Mustangs & MoPars(dealer accessory).

13) There are several well-known authorities who restore original Hood Tachs to include
re-silk screening the original face, new circuit board, rebuilt or new movement (head) and
case/trim repair/replacement This would be for the concours types as prices can exceed the
$250 or so for a new repro unit.

NOTE:
IF YOU HAVE CORRECTIONS TO THIS INFO, PLEASE LET ME KNOW. THANKS.

John
RamAir@comcast.net
Eph. 4:32