The "G" heads also required a quick pass under the surface grinder to bring the compression ratio back up to the stock ratio. This was required as the Turbo II short blocks weren't released until 1987 and were therefore designed for use with the newer, small-chamber, high-swirl head castings. The cut Dave had to make to this head then required a modified timing belt tensioning arrangement and a shorter belt. Now that Mopar Performance has released the ready-to-go head, based on the '86-up casting, none of these mechanical gymnastics are required. You simply ask the man for one of part number P4529353 and bolt it on.
Be certain that you use a Turbo II head gasket, as the cooling passages are different than the "I" motor.
The camshaft, followers, and retainers are all stock '84-'87 Turbo pieces (flat follower). The cam is installed at 114 degrees c.I. Note that '87 cams are the same, whether for Turbo I or Turbo II. The '88-up roller cams offer less duration and overlap for better idle quality and emissions, and should therefore be avoided in a performance build-up.
Valve springs are Mopar Performance race, part number 4286540.
The intake manifold is a stock Turbo II piece, carefully port-matched where the two halves mate. At the throttle body mounting pad, a die grinder is used to open up the throat to match the output of a 52mm throttle body from a 1987 3.0L Mitsubishi V-6 mini-van motor. Watch this, as the later 6s used a smaller, more restrictive, 46mm throttle body.
For a turbocharger, Dave chose the Mopar Performance "plus" unit, which features a high-A/R ratio. The intercooler, radiator, and associated plumbing are basically stock Shelby GLH-S items.
The air cleaner should have the zip tube cut off and an aluminum plate fabricated (to close off the hole) pop-riveted into place and sealed with RTV silicone sealer. Both of the hoses shown in the parts list will have to be shortened because of the shorter engine bay. Recent experimenting has shown that a '91 Spirit R/T hose is a perfect fit. The hoses do not have the ribbing like the stock pre-'89 Turbo II hoses. On Dave's car, the swap to the unribbed hoses were worth an incredible 3 tenths and 3MPH in the 1/4 mile. The air cleaner is mounted further rearward than in a Daytona so the hose from the power module will be in line with the air cleaner. Do not run without the inlet hose, the warmer underhood air will slow the car down.Previous - Next