Yea, we recently built a 3.2 to 3.4 twin plug, 964 distributor, big valve heads, etc. the 3.2 to 3.4 only requires the larger p&c’s. You don’t have to twin plug it to go bigger. We stick with the stock motronic but remapped a custom chip. You’re not gong to find a listed price on the internet to make the changes but parts are easy to price out and if you are doing the work yourself, then labor is “free”. If you are sending it out, then labor is whatever your builder charges, there’s no standard rate.
We rebuilt the transmission with custom gears. I think that mod tends to get overlooked when building a hot rod. It’s not cheap but makes a big difference on the overall drivability of the car.
