New motor being built. Currently I'm running the 289. It has a lot of RPM potential, and some decent torque, but I'm at a point now where I would like to give up a little RPM (go from 8k down to 7K as a max RPM) and increase the torque a bit. The new motor is a stroked 351W that will displace 383 CID (6.3L). I chose this combination over the larger stroker kits because it uses the longest rod of all the other combos which provides a nice rod length/stroke ratio, so my RPM limit will not be hurt too much with the stroker. The oil pan had to be cut up and re-welded to fit the crossmember set-up.
Fabricating the Headers
The headers were finished today. Now I understand why headers are so expensive. I had to fabricate new headers because the new AFR heads have a different bolt pattern than the old heads have. Also, the headers are so tightly fitted to the car that even if I could use the old heads, the fact that they will now be 1" higher and wider in the chassis would prevent me from using the old ones. Here you see the 2 X 4 wood used to mimic the OEM frame rail to ensure the headers would clear everything when finished.
After sending the headers to Jet-Hot for a nice ceramic coatings. A trial fit of the 383 into the Z engine bay. The left photo shows the motors sans the headers getting fitted and angle matched to the differential. The right photo shows the headers in place. The header jig worked perfect and all built-in clearances between the steering rod/ frame rails/ T/C bushing bosses are perfect.
View of the completed motor from directly over the top and from the right front. The tower brace became an issue when the new larger diameter, and taller distributor was installed. This required a re-design of the brace and offered an opportunity for Roger Berry to design and build an custom-made tower brace that cleared the distributor, and added a great deal of art to the engine bay. Component parts, all made out of aluminum are in the right photo.
G-Force Gearset
In order to make the transmission survive the increased torque (increased from 295 to close to 500 lb/ft), I installed G-force gears and cluster gear along with the mainshaft. Often overlooked on this upgrade is the overdrive gearset (5th gear). After investigating the many failures with the OEM overdrive gearset on high torque motors pulling hard in 5th gear, I also chose to upgrade it. Below are photos of the 5th gear compared to the OEM gearset. The G-force gears are on the left side in each photo.
Oil Cooler Install
The larger (6.3L) motor is fully installed and running at this time. Significant changes from the previous smaller motor are more power and torque, and more heat, specifically, oil temperature issues. The 289 rarely had oil temperatures that exceeded 210º even in the heat of summer, but the 383 now routinely has oil temperatures exceeding 245º. In an effort to reduce oil temperatures I've installed a cooler at the floor of the radiator intake duct, horizontally mounted, and next to the radiator. A recent test drive in 101º temperatures (Arkansas summer) indicated a max temperature of 210º. This was a 35º drop, which was expected and indicated good airflow through the cooler.
The left photo below shows the oil cooler installed beneath the floor of the radiator intake duct. A hole was cut in the duct (shown from the front of the car in the right photo). Air entering the duct must exit through the radiator and the oil cooler. The hole cut into the floor is not as noticable as I first thought it would be.
