Hi, I picked Up a 1987 300TD recently and I thought It had pretty underwhelming power. I discovered A missing bolt for the intake crossover which helped throttle response, I have Also used diesel purge, replaced the fuel filters, and also found a vacuum line from the ALDA to the bypass switch that was disconnected. I was Able to get the 0-60 time from 23 seconds to 13, however I wanted To see what typical full throttle shifts should look like. I’m having an issue with 1st gear getting to 3800-4,000rpm and hanging until I lift, 2-3 happens at about 4,500rpm. What should I check First?