Found some interesting info on Kenne Bell testing a 4.1:
Smokey Yunick's 5-step dyno test
4.1L Buick V6 with stock 4 barrel intake and Qjet carb 152 HP
Weiand intake manifold and Holley 600 CFM carb 170 HP
Weiand headers 175 HP
Crane H-214/2867-12 cam 202 HP
Bowl port heads 230 HP
Kenne Bell Level 1 Package
HP HP
Total Increase
125 -- Factory HP 231 V6
150 25 KB Number intake manifold
160 10 Holley 390 CFM carb
182 22 KB Mark 1 (dual pattern) cam kit
194 12 9.25:1 compression pistons
197 03 KB windage tray
200 03 KB oil pan
210 10 Mark 2 cam
Kenne Bell Level 2 package
240 30 KB ported heads
245 05 KB needle bearing roller rockers
250 05 headers
Kenne Bell drag testing (note: the info below has some tests from 1977 Skyhawk mixed
in with 1979 Skyhawk tests).
Test MPH ET HP
1 74.1 16.60 95 1979 Skyhawk w/KB oil pump kit and grooved main bearings,
7" slicks, stock gears, 2850lbs, 3050 lbs w/driver
2 75.0 16.50 100 KB flex fan and fan spacer kit
3 76.0 16.40 104 KB advance curve kit
4 76.5 16.10 104 4.10 gears with KB ring spacer
5 77.6 16.00 109 replace catalytic converter and muffler with KB parts
6 77.9 15.98 111 conventional 1 1/2" 3 tube headers
7 78.6 15.90 114 conventional 1 5/8" 3 tube headers
8 80.1 15.73 123 KB81031 1 5/8" 3-in-1 headers
9 83.3 15.34 137 KB Mark 1L cam kit (recommend KB roller timing chain,
cam gasket kit and front cover seal)
10 84.3 15.23 142 KB Mark 1X cam kit (cut guides and install KB seals with
0.060" retainer clearance)
11 86.0 15.12 152 KB Mark 2X cam kit
12 no change Rhoads lifters
Note: Cam and headers were tested with stock 2 barrel carb and intake. Had the
4 barrel carb and intake been tested first, increases would likely have been
larger.
13 87.1 15.01 157 KB19904 oil pan, KB19801 windage tray
14 88.0 14.91 163 KB crank, water pump and alternator pulleys
15 90.2 14.70 174 KB Number 1 intake manifold with stock 2 barrel carb
16 92.5 14.56 187 KB Number 1 intake manifold with KB jetted 500 CFM Carter
17 93.0 14.50 190 KB Number 1 intake manifold with KB jetted 625 CFM Carter
18 92.0 14.60 184 KB Number 1 intake manifold with KB jetted 400 CFM Carter
19 91.0 14.70 178 Heat KB intake runners to same temperature as conventional
manifold.
20 92.0 14.60 184 Cool runners
21 92.0 14.70 184 KB Number 1 intake manifold and KB jetted Holley 390 carb
(recommend KB EGR block off plate, heat isolator gasket)
22 93.3 14.55 195 KB blocked off heat riser (gasket or plates)
23 92.0 14.70 184 install stock air cleaner
24 93.3 14.55 195 KB46007F polyester max-flo low profile air cleaner
XX 94.1 14.41 196 Ram air (4" hose through headlight or hood scoop/cowl)
Note this test had 400 CFM Carter and did not have
blocked off heat risers
25 94.8 14.39 207 KB61003S budget forged pistons 10.2:1 compression ratio
26 94.8 14.39 207 KB50004 7000 RPM cast pistons 10.2:1 compression ratio
27 94.8 14.39 207 KB60003 Superlite forged pistons compression ratio
28 89.8 15.14 168 change to Edelbrock #5486 dual plane intake
(same 6000 RPM shift points)
29 89.8 15.06 168 lower shift points to 5000 RPM
30 94.8 14.39 207 re-install KB Number 1 intake manifold
31 95.9 14.29 214 KB11804-KB11904 Stage 1 valves only
32 97.4 14.12 221 ported and polished high port heads w/KB Stage 1 valves
33 98.5 14.01 228 KB Mark 2R cam
34 no change Rhoads lifters
35 100.0 13.87 240 KB Mark 3R cam kit
36 no change KB Mark 3RS cam kit (same design as 3R but solid lifter)
Note: 10.2:1 CR will run fine on 92 octane, use Rhoads lifters on Mark 2R or 3R
cams to smooth out for street use
37 101.9 13.72 250 KB 12:1 compression ratio pistons
38 102.8 13.64 255 KB9301 roller rocker arms
39 102.8 13.04 255 10" x 29.5" slicks, 5.13:1 gears and Doug Nash 4 speed
40 103.7 12.93 263 KB aluminum pulleys
Note: The above 12:1 compression engine can be run on the street but requires
100 octane fuel.
The following tests are for a competition only vehicle. Engine was rebuilt
with heavy duty block and rods, studs, MSD ignition, scattershield, steel
flywheel, etc. Suspension was also optimized for drag race (Ron Cosner front
and 4 link rear).
41 104.0 12.89 266 blueprinted engine
42 no change increase bearing and piston clearance 0.001"
43 106.1 12.59 278 KB Mark 5RS cam
44 109.4 12.31 304 KB82-7342 roller cam kit with Crane roller lifters
45 110.5 12.20 311 Mr. Gasket electric water pump kit
46 111.3 11.99 323 13:1 pistons
47 no change KB/Howards aluminum rods
48 no change install identical odd-fire engine
49 115.0 11.72 358 install identical 252" engine
50 124.0 10.80 442 Ported Stage 2 heads, KB roller rockers, head studs,
cam kit, 3-in-1 headers, Edelbrock Stage 2 intake
manifold
51 125.0 10.71 451 Change to 750 Carter or Holley
52 no change Milodon gear drive
53 122.1 11.00 Powerglide tranmissions and 7" high stall converter
54 126.4 10.60 493 276" stroker V6 with powerglide
55 129.0 10.30 493 Doug Nash 5 speed transmission
Note: KB ultimately turned 9.18 @ 146.5 MPH in 2400 lb car, breaking
the NHRA record