Aaron's 3.4 DOHC 88GT Build Thread
Posted: Sun Jan 29, 2006 10:52 pm
It seems I have like 5 threads associated with my swap, so from now on this will be the one and only. The admin can delete the "I'm XXX poorer and one step closer thread." I have not yet physically started the swap yet, just collecting parts for now, which is all but completed. The car is my 1988GT, factory 5-speed.
I will be using a 94-95 ECM, which is OBD1.5, the SFI version of OBDI. It is more accurate and thus makes more power and better MPG.
I purchased a 94-95 3.4 DOHC crate motor off of Ebay for $1000. I pulled the heads, and they are in SOuthern California getting a full port/polish, and reshaping of the ports altogether. Basically redesigning the entire port shape. This job is valued at over $2000, and I should have them by Spring Break. Above them will be a set of 48g lifters (MUCH lighter than stock)
The oil pan will be pulled off and reshaped to add 1-2 quarts of oil capacity in order to not dry out the bottom end under frequent 7000+ rpm runs. I'd like to eventually run this motor reliably to 8000rpm.
The cams will be stock for now with a 13* exhaust retard. Eventually I will add lash caps for added lift and regrind the cams with a smaller base circle and wider duration.
The intake manifold will also be stock for now, just port matched. With the new cams will go a fully independent throttle body setup made by TWM Induction. This features 6 independent 48mm throttle blades, a GM TPS sensor port, relocated injector bungs with fuel rails, and 6 50mm air horns. I'll be building a custom lower intake to which these will mount and stand up vertically. The exhaust manifolds will also be stock for now, but with the cams and intake I'll be building a set of long tube, tuned equal length headers measuring 1.75" x 34" primaries with dual 2.5" collectors. I have built a set of equal length headers for a 3.4 DOHC before, and look forward to doing this.
I will be blocking off the factory water pump outlet and using a Davies-Kraig Electric Water Pump with controller. This will also act as a thermostat, and will regulate voltage according to coolant temperature. Thus I do not need the typical thermostat.
I will be deleting A/C and power steering as well. The only accessory on the motor will be the alternator, and it will have the stock 6-rib belt with a FFP UnderDrive pulley.
I have already purchased a brand new Spec Stage III clutch and Fidanza aluminum flywheel. I also have the engine mounts, I'll be using 4 Dodge truck mounts to mount the engine about 1.5" lower than it would be on factory 2.8l mounts. I will also be adding dual poly dogbone mounts, but I won't build those until the motor is on the cradle and in the car.
I still need to buy a starter, fuel lines/adapters, coolant lines, UD pulley, and a few other small things. I look forward to starting the actual swap as soon as I get home for summer break.
How about some pictures? (Ask if you want to see more, I literally have a few hundred)
The car (1988 GT 5-speed, factory gray leather, Kenwood Double Din MP3 Player, aluminum overlays, SpeedHut reverse glow red gauges w/ a 185mph speedo and 8000rpm tach, otherwise stock) and the operator:

1994-1995 Wiring Harness, complete with a Darth chip, ALDL connector, O2 sensor, IAT sensor, ECU, and a MAF sensor. Picked this up just today:




Davies-Kraig Electronic water pump with controller, picked this up on Ebay:

SPEC Stage III Clutch:


Fidanza aluminum 8lb flywheel:

Brand new alternator I picked up on Ebay for $46, and local pickup!

I will be using a 94-95 ECM, which is OBD1.5, the SFI version of OBDI. It is more accurate and thus makes more power and better MPG.
I purchased a 94-95 3.4 DOHC crate motor off of Ebay for $1000. I pulled the heads, and they are in SOuthern California getting a full port/polish, and reshaping of the ports altogether. Basically redesigning the entire port shape. This job is valued at over $2000, and I should have them by Spring Break. Above them will be a set of 48g lifters (MUCH lighter than stock)
The oil pan will be pulled off and reshaped to add 1-2 quarts of oil capacity in order to not dry out the bottom end under frequent 7000+ rpm runs. I'd like to eventually run this motor reliably to 8000rpm.
The cams will be stock for now with a 13* exhaust retard. Eventually I will add lash caps for added lift and regrind the cams with a smaller base circle and wider duration.
The intake manifold will also be stock for now, just port matched. With the new cams will go a fully independent throttle body setup made by TWM Induction. This features 6 independent 48mm throttle blades, a GM TPS sensor port, relocated injector bungs with fuel rails, and 6 50mm air horns. I'll be building a custom lower intake to which these will mount and stand up vertically. The exhaust manifolds will also be stock for now, but with the cams and intake I'll be building a set of long tube, tuned equal length headers measuring 1.75" x 34" primaries with dual 2.5" collectors. I have built a set of equal length headers for a 3.4 DOHC before, and look forward to doing this.
I will be blocking off the factory water pump outlet and using a Davies-Kraig Electric Water Pump with controller. This will also act as a thermostat, and will regulate voltage according to coolant temperature. Thus I do not need the typical thermostat.
I will be deleting A/C and power steering as well. The only accessory on the motor will be the alternator, and it will have the stock 6-rib belt with a FFP UnderDrive pulley.
I have already purchased a brand new Spec Stage III clutch and Fidanza aluminum flywheel. I also have the engine mounts, I'll be using 4 Dodge truck mounts to mount the engine about 1.5" lower than it would be on factory 2.8l mounts. I will also be adding dual poly dogbone mounts, but I won't build those until the motor is on the cradle and in the car.
I still need to buy a starter, fuel lines/adapters, coolant lines, UD pulley, and a few other small things. I look forward to starting the actual swap as soon as I get home for summer break.
How about some pictures? (Ask if you want to see more, I literally have a few hundred)
The car (1988 GT 5-speed, factory gray leather, Kenwood Double Din MP3 Player, aluminum overlays, SpeedHut reverse glow red gauges w/ a 185mph speedo and 8000rpm tach, otherwise stock) and the operator:

1994-1995 Wiring Harness, complete with a Darth chip, ALDL connector, O2 sensor, IAT sensor, ECU, and a MAF sensor. Picked this up just today:




Davies-Kraig Electronic water pump with controller, picked this up on Ebay:

SPEC Stage III Clutch:


Fidanza aluminum 8lb flywheel:
Brand new alternator I picked up on Ebay for $46, and local pickup!