Stall on a Stock 904 Converter?

If it was mine,I would pull a head off and measure stuff. I have reused head gaskets two and three times.
But failing that, like T-N-T says,2800 will get you back some grunt.
And that rear has got to go. Someone said your car will be a turd to 30mph. I say more like 40.
The engine won't wake up until maybe 3500rpm.Those 205/70-14s are about 79.5 in circumference.
So
(3500x79.5)/ (1056x2.71x2.45)=39.7mph. Getting to that 3500 is gonna be the big deal.But I guess that teener might spin one of those skinny donuts, so it might not be so bad. At least until the spider-gears seize up...............
But, I can see the disappointment on your face already. So with the lack of compression,you are gonna need 4.10s to get going by 26 mph, and at least a 2400 to do so with any kind of authority.
3.55s will make it 30mph. But the loss of torque multiplication means you need more TC;perhaps 2800
Of course a DP carb, well tuned,might make the 3.55s move out a little better.... Oh wait, no compression,scrap that idea. No compression means, the engine will likely bog,perhaps big-time, with a DP,even with 3.55s and a 2400.
At this point getting the compression up to where it needs to be is still cheaper than all the other options. And waaaay more satisfying in the end. If you boost the Dcr up to 8 or even 8.2, you may get away with the stock TC. And I bet you were gonna put 3.55s in it anyway. And at that point,she will be ready to rock.
So, a Static C/R of 10.3 would get you a Dcr of 8.1 and 162psi; a really good start. This Scr, requires a total chamber volume of about 71cc. That is doable, with teener heads.But you are gonna need to get the pistons way up.Ima thinking Zero-deck.
So a new set of pistons,a bit of machining, plus 3.55s and a suregrip for that 7.25,and the stock TC(which will now stall probably up to 200 rpm higher); versus a big TC and 4.10s,and still the suregrip. Since the current pistons have never run, they are still worth good coin.In the end,perhaps a bit more money spent, but a way funner combo. And better fuel mileage to-boot.
I know what I would do. But I'm used to backing up and starting over:( I have made a lotta mistakes over the years. But one of the worst was camming up a stock-compression 73 teener with 2.73s and a stock TC. I must admit tho, it did have pretty good passing power................. at 70plus mph..............kicked down into second!