As I said, I have all your DC-8 models and all the Military 707 variants, the 727's ... and more.
"SPLITPIN" .... in the case of the HJG DC-8 flightline ....
We upgraded these during March of last year .... and also vastly expanded our line to cover "the entire DC-8 family" at the same time also (simulated weight and engine thrust, as well as adjustment/s to certain drag related parameters also, being the primary factors which dictate the new and improved DC-8 performances within FS). I just want to say be sure you're using the current "V5.4" HJG DC-8 base packs (the version number is stated within a header at the top of each CFG file). If you're not sure which version you have .... then .... replace "the lot" .... and add your current textures to these new base packs. Our DC-8 soundpacks are "COMPLETELY NEW" also .... released during March/April of last year. These soundpacks are now available as separate FS2004 and FSX versions .... and are the "real McKOY" having each been recorded from real world data. We've also fine-tuned a couple of gauge placements within each of our DC-8-10/20/30/40/50 panels also. You can read about all of this per the following HJG DC-8 manual ....
http://tonymadgehjg.proboards.com/threa ... ling-notesAll technical queries to the HJG forum though please

In the case of the HJG B727 flightline .... and I hasten to add what I'm about to communicate relates to the
"B727-200's ONLY" at this stage ....
We upgraded and similarly expanded our B727-200 inventory with "NEW" 3D models and FDE during October 2015 .... also adding a couple of "NEW" panels .... AND .... releasing "BRAND NEW", and separate, customized (from real world recordings) soundpacks for FS2004 and FSX too. The new B727-200 base packs and FDE are each branded "V2.0" (most conspicuously identified per the header within the top of each CFG file). Again .... and for best enjoyment .... make sure you're using these latest files. One "CAUTION" I do need to draw everyones attention too though is in regard to the new 3D model names .... versus the MODEL= data line stated within the ADD TO AIRCRAFT data for each/most B727-200 texture files. Each base pack containes new models and FDE .... as stated above .... BUT .... by the time we employed these new models the existent HJG B727-200 texture inventory was far too large for us be able to edit the MODEL= data line for each individual texture (all of our B727-100's are as yet "totally unaffected" by this minor imposition .... new models for these have been compiled also but have yet to be uploaded) and then reupload the whole lot, so, as stated within the new installation instructions, which accompany each texture, everyone needs to "manually edit" the MODEL= data line with the name of a particular model folder from each base pack. This's an unavoidable imposition .... under the circumstances (and which does trap those whom don't read the instructions and manual) .... but .... HJG's just a very small group of volunteer FS enthusasts and with limited resources at its disposal. If you .... or anyone else .... get stuck .... or confused .... in regard to any of these installations .... THEN .... post, or drop me a PM at HJG and I'll try'n sort everything out for you. PLEASE NOTE THOUGH .... FS20o4 is muy particular specialty and not FSX. You can read about all of this per the following HJG B727 manual ....
http://tonymadgehjg.proboards.com/threa ... ling-notesIn the case of the HJG B707/B720?and C135 SERIES flightline ....
We're currently fiddling with our FDE at the moment .... for the B707 and B720 .... in order to improve a few performance related characteristics (particularly in regard to approach to landing attitude with full flaps), but, progress is slow going .... whilst going .... due to other HJG project priorities at the moment. Here's a recent report I drafted in regard to what we're actually doing .... and intending to improve .... for our B707's and B720's .... but .... it'll be a while before these modifications are actually released though since each simulation has to be assessed, and adjusted, individually, to reflect the right performce ....
http://tonymadgehjg.proboards.com/threa ... -on-momentHope you .... and everyone else .... finds these details interesting if not helpful too

Mark C
AKL/NZ & BOG/CO
HJG
simviation.com/hjg