Ok, I will explain more of the points I made.
We decided as a team to do a trans swap. The T350HD was already a better choice as the case is stronger and has an updated synchro design. This also means setting the diff preload. The T350HD has slightly better ratio’s. If your lucky you may even find the 4.12 ratio if not 3.91 is it.
The T355 is used mainly for parts. It has a updated synchro for the 3/4 cluster. That does not have the issues with shift keys falling out. It’s a carbon synchro and can handle a lot of abuse. This part can’t be bought so you can only find it in yards.
The no 90 intake is an easy mod for HP. We took the hit for a intake mani. The best all around intake you can find is an AMM fab intake. The no 90 intake mod can get you most of the way there but we live in a series where you need to maximize points to HP gained. The other key part is the power no longer dies off at 5800-6000. In the later parts we revved out to 6500. Which was a big gain.
The stratus head has bigger valves and stock vs PT has a better cam profile. The early 01-02 heads were designed for boost. But with crazy Chrysler ways they put the head on NA cruisers. As if you were buying a NA cruiser you probably weren’t after performance. The stratus head also makes it easier to use the available performance intakes and such.
The shifter is a key part for trans longevity. We had the issue a couple of times of our 3/4 shift key falling out of the synchronizer. This is not always due to stretched cables but over extending the shifter lever itself. Let’s say you have a over zealous driver that when heated bangs the gears a little harder than usual. The extra force he puts in can dislodge the shifts key from the synchro. The mad dog shifter reduces the throw with no extra effort but also adds rod breaks which will prevent the over extending of the lever. It’s cheap insurance.
The 1/4 hole was already answered above
DOHC headers are still easy to come by. The best company is TTI. They used to make a race version with a step mid way but they are no longer made. The next best thing is to take your stock TTi and lop off the dump merge. We purchased a vibrant 4-1 true merge collector. Back to back dyno the merge was good for 5-6 hp. On top of the gains for the header.
Two years into our adventure with endurance racing a 2.4 neon (2012). We were losing clutches due to broken pressure plates about every 4-5 races. So we changed them every four races. It was always the same failure. We originally thought it was a clutch issue as the Mopar performance clutch changed mfg’s. So we bought an ACT. Worse mistake ever. The added stiffness of the pressure plate really hurt the internals. We found you couldn’t shift as fast with it. We also still had the same problem but now with breaking $300 flywheels. Fast forward to 2013 PRI. We talked to ACT about our issues and they wanted to see our flywheel. They ruled it was torsional vibrations. Seeing as we had deleted our balance shafts this made the problem even worse. We decided to give an ATI a try. Not cheap, but we could tell a difference right away. Now clutches are lasting almost 12 events, seals, rod bearings are all lasting longer. I don’t say an ATI is a must but if you were going to run a lot of events like we did (6-7 a year) it really helps.
Dyno mod list:
AMM Fab intake manifold
TTi header with custom vibrant merge
stock 2.4 stratus cams
Balance shaft delete
MS3pro Evo ECU w/K coil ignition