I've had the Grand Prix for about
4 years--as of October 2004. I got it from a friend who owned
the car for over 20 years. He bought it from another friend who got
it from the original owner, meaning I'm the fourth owner.
The friend I got the car from didn't drive it much but spent
a lot of time working on it. In over 20 years of ownership he put
about 5,000 miles on it! When I got the car, it had just under 120,000
miles on it and it now has about 137,000.
I recently (summer of 2003) removed the original 370 horsepower
428 and installed a new one--bored and stroked to 468 cubic inches. Here is some info about my car:
||7.7 litres (468 cid:1969
428 cid XF block bored "65" over with a 4.25" stroker
||950 CFM Holley HP double
pumper with 1/2" baseplate, mechanical secondaries
||Polished Edelbrock Torker
II port matched to heads
||72cc Edelbrock aluminum
ported to flow 300 CFM @ .500 lift & 28" by SD
Performance, 2.19" intake & 1.77" exhaust valves,
Harland Sharp 1.5:1 roller rockers. Heads were provided "complete" & ready
to install by SD Performance.
||Ross custom forged 20
cc dished pistons weighing approx. 455 grams ea. plus lightweight
pins; approx 10.25:1 compression
||Eagle cast crank with
4.25" stroke, 3.25" main journals & BBC rod journals,
||Clevite 77 mains & Federal
Mogul rod bearings
||Eagle "H" beam
6.8" BBC with ARP 2000 bolts
||Melling high volume pump,
Canton road race pan with windage tray & crank scrapper with
relocated dual oil filters.
||Comp Cams "solid" flat
tappet custom grind to SD
||Double roller with billet
||CAT SFI approved
||Powerbond SFI approved
||Rodney Red 2 row aluminum rad with built-in transmission cooler & shroud with 2 Permacool 1,620 CFM electric fans (ea.), a Milodon high volume waterpump, & high flow 160 degree thermostat.
||Hooker "Super Competition" with
2" primaries into 3 & 1/2" collectors; 3 & 1/2" exhaust to the tailpipes. Lejeune Race Cars shortened the headers for more ground clearance and installed an "X" type crossover. The tailpipes are Torque
Tech. Mufflers are Flowmaster 50 "Big Block" mufflers with 3 & 1/2" inlets
and outlets. Initial installation from headers back by Roy at Island
Muffler, who did a great job. Click here to listen to a clip of the car idling & reving just a little.
||GM HEI with MSD coil & 8.5mm wires
||2 high volume electric
(Holley; one for normal driving & one for nitrous system)
||200 h.p. Nitrous Oxide
||Turbo 400 with HD belts & clutches, "dash
two" shift kit & TCS 2800 RPM stall convt & B&M "Megashifter"
||Stock 12 bolt "posi" with
3.08 gears & TA Performance "Girdle"
||Stock, with custom coil springs to lower the front end 2 inches, plus Monroe "Sensa-Trac" shocks
||Billet adjustable upper trailing
arms & solid billet lower trailing arms with Monroe adjustable "E" shocks
set to "firm"
8" x 15" all 'round
||Goodyear Eagle NT 275/60R15
||Engine has been balanced,
battery in trunk, kill switch, fuel switches, nitrous switch,
and nitrous button between seats. March serpentine system has replaced stock pulleys and belts.
- MSD "Soft Touch" rev limiter
- Electrical relays to radiator fans
- Electrical relays to headlights
- Remote solenoid
- Engine kill switch at the bumper
- BF Goodrich Drag Radials for rear (295/65R15)
- BF Goodrich radial TAs for front (235/60R15)
- "Firewall" between the trunk and back seat
- Driveshaft safety loop
Dave Bisschop at SD
Performance gave advice on engine parts & assembly,
as well as providing many of the parts. Dave is one of the
premier Pontiac engine & head builders anywhere. If you've
got a Pontiac engine project or need head work of almost
any type (e.g. Ford, Mopar, Chev, Import), Dave will provide
you with world class work at a very competitive price. Ask
anyone who knows anything about Pontiacs and they'll tell
you Dave is one of the best, as well as being one of the
best "stand up" guys in the performance business.
All machine work--align boring, cylinder boring, rod sizing,
et cetera by Dean at Cords Engine Specialists.
Neither the engine or the car has seen a dyno. The car may get run on a chassis dyno some time in the future but it's unlikely the engine will get dynoed--after all it's in the car.
That being said, according to Desktop Dyno 2003, the engine makes around 511 horsepower at 5,500 RPM and 524 foot-pounds of torque at 4,500 RPM. But at only 2,000 RPM it's supposedly making 418 foot pounds of torque!
||Information coming as
soon as the new engine is broken in and run at either Western
Speedway (Vancouver Island) or Mission Raceway.