Well that is interesting. You definitely want to replace the heads. I am assuming those reso heads have been around for ages and were cheap to begin with. There are some threads on the forum about head combinations that tend to work well on MIJ kits. Ther are a lot of guys here that had success with them.
I am not sure what to suggest head-wise. I am sure the reso head will be a single ply. Clear heads tend to give you a little more open sound with increased sustain. Coated heads would look more authentic and would darken the tone and decrease sustain somewhat. As to batter heads, that is tough based on your comments. You mentioned 'tighter', and 'seventies'. In the generic sense that is a bit of an oxymoron as so much of the seventies have been defined by the highly muffled concert tom sound. It seems like that is not what you are after. When you say tighter, that makes me think more in terms of a coated head. A single ply head will probably help add some life to the drum if you are not an overly hard hitter. You can always add a touch of Moongel to dampen things a bit.
Once you choose a head combination I would suggest starting with both heads at the same pitch and get that pitch as low as possible. Listen to the drum at that point. Then raise the pitch slightly on both heads a half step at a time. (maybe a quarter turn or less on each rod) Each time, check that the heads are in tune with themselves and with each other. Then listen to the drum and take note of the changes, not only in pitch but in tone and character. At some point the drum will choke or become lifeless as you have mentioned. Some drums have 'dead' zones in them and you can keep raising the pitch and eventually get an open tone again. You can try that and see. It doesn't happen very often to me though.
Once you have done that, you will have found the complete range of the drum. Tuning the heads to the same pitch will allow for the most sustain and lends itself to a really open and musical tone.
Next, I would drop back to the lowest possible pitch and get everything back in tune. As a side bar, I don't know if it really matters, but I always tune below my target pitch and then come back up to it so that the last thing I do to a tension rod is to tighten it and not loosen it. Anyway, once in tune, try raising the pitch of the reso head. I usually raise it a minor or major third. Listen to the drum again and notice the difference in the timbre or tone of the drum. Then begin raising the pitch on both heads a little at a time as before only now with the interval between heads.
Once you have done that, although time consuming, you will have a pretty good idea of what that drum will and will not do. You may find that these drums have a really limited tuning range. That would not be overly surprising. I think the goal for dealing with any drum or any kit is to find out what it does well and then let it do it. If what it does well is useful to you then great. If not, sell it or trade it and try something different. Every drum has it's own unique character. That's why some guys here are die hard Gretsch or Ludwig or Rogers, etc. fans; they have found a sound that they an relate to and it produces what they hear in their heads. That is also why many of us have different kits. They all have a unique and distinct sound. You will just need to figure out what the character is of your Pearl kit.
Good luck and let us know how it is working out. I hope this helps.
