1973 Pontiac LeMans
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- 1968 400 (290 HP) YC Auto 10.5CR Block Casting # 9790071 (production
- Bore: 4.12 (stock) + .040 overbore = 4.162
- Stroke: 3.75 (stock)
- 408 CID
- Zero Deck Height
- 1968 #16 castings (H.O.)
- Bowls blended
- Intake ports ported and matched to intake manifold.
- Intake flow rate is 280 cfm.
- Exhaust ports were ported to flow 240cfm
- Compression ratio (with head gasket installed) is 11.15
- (Fel Pro gasket: thickness, 4.300 in. gasket bore, 9.4 cc compressed
volume, .039 inch compressed thickness)
Camshaft: Comp Cams Solid Roller: Lobe lift is .400inch. Gross
valve lift is .600 inch lift on both intake and exhaust. Duration
@.050 lift is 265 degrees on int. 270 degrees on exh.
- Comp Cams Solid Rollers
- Comp Cam 917 Springs
- I.D. .824
- Seat Load email@example.com
- Open Load firstname.lastname@example.org
- coil bind 1.050
- rate 566lbs\in
- titanium retainer 731/720
- steel retainer 741
- cup seat 4700/4785
- shims 4757
Valves: Ferrera Race valves 2.11 intake and 1.77 exhaust.
Pushrods: Comp Cams: 5/16 stock length
Rocker Arms: Crane Silver 1.65
unmodified RPM performer
Carb: – 1050 Dominator (overkill for this application –
900 would get it done, but this is for keeping up with future upgrades)
Fuel Pump: 140 GPH Mallory Fuel Pump
Fuel line: -8 steel braided lines (½ inch) run from fuel
cell in trunk to pressure regulator on firewall to carb. (all STRAIGHT
Fuel pressure is typically 7- 8 lbs.
Coated Hooker Super Comps 1 ¾ inch headers, 3 inch collectors.
Exhaust is dumped at the track AFTER the Performance Years 3”
Pypes X cross over.
GM HEI recurved by Larry Rowe
MSD 6al box
Plug wires: Taylor 8mm
Turbo 400 with reverse pattern Cheetah manual valve body.
Continental 3800 Stall converter
3 inch tube with 1350 series U-joints
GM 10 Bolt: Spool with 4.10 Richmond gears.
Front: 90/10 Summit drag shocks – no sway bar
Rear: 50/50 Summit drag shocks. Air bags. Boxed upper control arms.
Polyurethane bushings all around.
Aluminum body mounts.
29.0x12.0-15 GoodYear Eagle Slicks (28 inch tire is better for
this application – these tall tires kill gearing, but were
too good a deal to pass up)
1973 Pontiac Lemans
Vehicle Weight: 3500 lbs
Race weight: 3675 lbs
Current HP numbers are 397.8 RearwheelHP and 452.8 RWTQ. Figure
18% loss through drivetrain you 468 Flywheel HP and 533 FlywheelTQ