I use Delta 40's, not 44's. 44's are race mufflers, whereas the 40 is quieter. I have the 3" resonator/Delta 40 2 chamber combo on my F truck and it's quiet enough to be ignored on the street.

all I know is flowmaster super 44s were deafening on BGDAV's 408, and ended up with a spiral flow in the tail pipe additionally and still got the cops telling him he should put it off the road on the spot.    replaced with a pair of the switched mufflers that are super restrictive when closed, but gets it away from the house or through cops without too much attention. 

All depends on what I'm setting up a Clevo for.   Mild street: Tri Y Headers to 2 1/2" Y pipe to 3" collector, 3" x 12" hotdog (with perforated internal tube, not louvers) for front resonator and Flowmaster Delta 40 3" muffler with 3" tail pipe.   Hot street/ drag: Tri Y headers with larger secondary pipes (min. 2 1/4" or even 2 1/2" to dual 3" to 12" x 3" hotdog resonators and dual 3" Flowmasters with dumps. A 2 1/2" balance pipe just before the resonators.  

Thanks Dave, those vids will be handy.

Will be doing that next. I'm guessing maybe something moved out of place when I was installing the pump and hopefully, not me creating an extra problem.

https://www.ebay.com.au/itm/176693782359?_skw=hooker+21502+mufflers&epid=2290978363&itmmeta=01JKH9JE4VA9VX7CGAWDBNSK89&hash=item2923c52757:g:1SQAAOSwBKVnSE9w&itmprp=enc%3AAQAJAAAA0HoV3kP08IDx%2BKZ9MfhVJKnJyYbj6qdmAE3Q7u9smjGJzL5Eic2xY5waf8xJrKGKCQ7doUEBbnztxvQE0ibUSpbyN3rdg5SipWkremV7sSBup1Q7h6CtHe4FeIrU3HSpVuBbr1Qv1XOh%2FSdCG1QEGanjflLkF%2FU%2BORvY8Wh0gqa6Tb8FPRqP7Uygbd3yS%2B3BK8KXIRfIFDvOt2yZAAIfv05xiPfFdnWAZjxd0pkg0x4KK9%2FHMTw8wUNVehKNlM%2BObTa7iNuLyWJihCORVd9gOlA%3D|tkp%3ABk9SR8jiyamcZQ     Just curious about the type/brand of mufflers people are running on their Cleveland's also would you guys recommend the Hooker aero chamber 21502?

At this point , since issues are presenting in both forward & reverse , really need a pressure gauge on there now see what is going on.   Shame you're so far away i'd take a look at it    It's got a ton of oil in it . Usually a deep pan and smaller converter is around 8-8.5 litres 

Update:   Had the car on stands to do more tests. Oil level is fine.  In Drive the wheels started turning in 2nd gear and stayed there, no 3rd. Manually went to 1st then 2nd then Drive still no 3rd. Drive to Reverse no probs. Now today it's making a metallic whirring noise while in Park or Neutral, no noise in gear.   Looking at the Tacho and speedo reading while going thru the gears, 1st 25kph @1500rpm 2nd 45kph @1500rpm Drive - no change   This time left it in drive and went up to 2000rpm and only went to 40kph manually dropped back to 2nd and went 58kph @2000rpm   Easier to pay more attention on stands then when driving on the road.    

Same, driveway slopes down a little from the road and is noticable when I'm reversing up and out to the road. Needed more revs than usual to reverse out   I think so. I was changing the gears manually, seems to struggle more in top gear. Honestly it feels like it doesn't have enough fluid but it does.   TCI Saturday Night Special Torque Converter 26-Spline  Stall 1600-1800 rpm  Part# 450900   They were unless they came apart while I fitted the pump to the box. Yes that one you see apart I fixed before installing.   Haven't changed anything. Just pulled the pump out to see if it was worn and put it back in.