"Factory Stock
Stage 2 Build"
Tom Rix's 1970 "Factory Equipped" Stage 2 GS
Originally owned and raced
by
Doug Jones and
Dave Benisek,
Tom's GS is one of the
rarest in existence.
We had the honored opportunity to replicate the Stage 2 engine for Tom's car.

1975 Block .038 over, Hardblok fill 1/2 way up. Lifter galley filled for reliability.
Stock Buick crank.

Carrillo stock size Buick rods (came in car when I bought) about 780 grams
Replacement J&E pistons to specs of Jahn's Stage 2 pistons, 12-1 version

Factory unmolested (no porting, blending etc!) Stage 2 iron heads, 3/8 Stage 1 TA valves. TA
1.385" springs, retainers and locks.
Flow figures:









Original Stage 2 Holley mount only B4B, unmolested except center divider cut down about 1/2 inch
the full length to match the notch in the back in the factory casting. (It was cut out for optional 950
Holley 3 barrel carb).

Stock 850 DP Holley carb #4781, choke plate still installed and no porting or grinding ,air bleeds
and jets changed. NO carb spacer!

Custom 107 "window rattler" cam trying to match factory duration with about .530 net lift (this is cam
approved by IHRA for the factory Stage 2 engine combo). TA solid lifters. With current technology
this cam is an improvement over cams that would have been available in the 1970's even though
the overall specs would be close.

TA 1.60 roller rockers (for reliability over the 1.59 ratio factory rockers) and 5/16 pushrods.

Kustom 2399 Factory Stage 2 headers (on dyno we used TA Stage 2 headers that were fitted with
EGT's but the overall design matches the Kustom's almost perfectly). Stock collectors.

TA custom 7 quart steel oil pan, timing chain and hardware used throughout the engine. ATI
external balancer and flexplate.

Except for a few changes for reliability, the B4B divider being cut down the1/2 " and the replacement
cam I believe it shows what this combo was capable of thanks to Dennis Manner and the Buick
engineers.

Dyno pulls were only made to 6000 (last pull to 6300 rpm) and it was not "flogged" for every last HP.
Only a jet and spark plug change. Timing at 34 degrees.

Factory estimates were 50-75 HP over the Stage 1 engine.

        597.7 HP @ 6,100 RPM
547.4 lb ft of torque @ 5,400 RPM
lift
.100
.200
.300
.400
.450
.500
.550
.600
.650
int
69
139
205
256
  263
267
270
273
ex
60
107
140
169
  191
199
205
209
Stage 2 dyno sheet
Stage 2 dyno graph
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A                         B                         C                       D                        E