"ok pepole you must be forgeting the litel fact that starfleet at the time of the epesods we are talking abult had a very limited amaunt of ships and was still using the TMP ships out of nesesaty not choise and wher probably canabolising ships in there junk yard and stuf"
WHAT??? This makes no sense. Why would the Federation canabolis old TMP ships too make due? During the TMP/TOS era their where fewer ships then their was by the mid 24th century, but I find it hard too beleive that the Federation had very few ships during the "Lost Era" (2300 - 2360). I have too imagine that the their are other designs similar too the excelcior and Ambassador classes (maybe even other ships) that use similar technology to compensate for needed ships. I could see refiting TMP ships with new technology and patching up damage and structure builds, but too literly tear apart old TMP ships and integrate them with New 24th century components would be a waste of time and resources when just refiting or building a new ship would be easier. I think Core, you ware getting confused with the DS9 Tech Manual where it indicates that the Federation Canabolised old ships with new Tech in order too make up for heavy loses during the Dominion War. This was an unconventional procedure, and most of the designs of the "Frankenstein Fleet" where for War purposes as the designs where not very effecient. The Feds just wanted too get available units on the front too make up loses, they were not intended too be useful ships for other purposes. besides, the Frankenstein Fleet designs required much more maintance.
As for specs for the Stargazer in SFC2, keep in mind that SFC2 is based on SFB rule procedures which are vastly different then Star Trek combat procedures (if their are any). That is why SFC3 is much different then SFC2. SFC3 is based on the Television show of TNG/DS9/VOY while SFC2 is based on the old board game of SFB. If I was too put in a Constelation in SFC2, I would try to stay with SFB protocal, otherwise the ship will be TOO powerful. For example, I would use 4 engines still but only make them about 10 in warp power, which is a total of 40 in warp power. Impulse Power is greater too as it has 2 Impulse Engines available which probably translates too an Impuls power of 6 maybe even 8. Even though the Constelations only have one Hull, it is very large and seems too acomadate more stuff then other Constitutions or Mirandas. I would also use Center Hull for this because the space frame of the design seems very sturdy. In SFB, Center hull ships can take more punishment before losing Warp Power then using 2 or more hulls. As stated above, It seems that the ships could easily hold a lot of Lab facilities and might be one reason why the ships are still in active use today (just refitted with more modern Lab Facilities). I also think its possible that the ship might have slightly more Transporters and Tractors given the extra space you are dealing with. As for weapons, If i recall, their seemed too be a huge Photon Torpedo Assmbly on the bottom of the hull. Although their much be the same amount of launchers as a standard Connie, its possible this whole assembly could be Turret assembly giving the ship great Photon Torpedo Arcs (much like a Plasma Turet assmbly). Phaser suit might be almost the same setup as a Connie with possibly better firigng arcs and possibly a larger amount of PH-3 Defense Phaser available. I think the sheilds for the Constelations are probably equivlent too the Connies (maybe slightly more). SFB never totally explained what dictated how strong a ships sheild should be, it might have been based on the type of ship (like a Frigate versus a Destroyer).
As for specs for SFC3, I'm not sure as I have not messed with the files much with that game. But the Daystrom Institutes website has a huge database of information and can easily be converted too SFC3 specs. Its a good site, you should check it out.