johns440rr1

This may be a silly question but, I have recently bought a nice 85 toyota that was somewhat well kept. Just about everything works including the brand new a/c system . In az. it's a blessing ! I bought it before i looked real close but as face value and a simple drivers test , i bought it for 3 K. 23.3 MPG and the a/c was the selling points :-D !
Come to find out the the previous owner had rebuilt the motor Approx. 60 K ago, around 2002 and didn't drive it allot. He didn't have available the receipts so i went to the place that rebuilt it ! Yup, They confirmed it ! ( another good selling point ! ) After further review and inspection I did a compression test and it revealed it's ugly side . #1~ 200 lbs, #2~ 190, #3 180 & #4 200, Soooo, i double checked them all ! WTF ? I went shopping for a "Toyota Manual" on ebay and bought it, Expensive little critter , LOL ! ! The Good book sez 175lbs. MAX ! That "should" would make #3 ok and the rest be well beyond the Max ! I did a leak down test and all are ok ie: very little , if any !
Well, #1 & #4 spark plugs are running hotter than a pop corn fart , 2&3 are ok ! The block shows signs of leakage at the head gasket between 1 & 2 , Ewww ! Is it posible that i can try to put a larger feeding fuel injector in each cycliner port to compensate the "lean running " cyclinders ? I'm yet to decide that the head is quite possibly warped and that would be the possible cause. Though The MPG is great @23.3 mpg but the head , i think , needs to be replaced !
I also know the Rebuilder of the motor because of pryor experiance. He rebuilt my 383 for a 1971 RR and screwed up #5 cylinder , or just forgot to do that hole ! All other stones fit as they should ,snug , #5 would not go into it's hole. I miked all stones and Yup , CNC machined and all weighed the same , GFF !
In other posts ..... I ran across a question for the double roller chain . It makes mechanical sense that the upgrade would be a little more reasuring knowing that the extra chain wouldnt hurt but, is it actually needed ? Like Chrysler or any other engineers evaluations when building a motor , I tend to think that they knew what they were doing when they designed and built the damn thing and i'd have to agree , they knew what they were doing.
Hmmm, Fix the head , right !?
I guess that i'm used to the 94 GMC's power.....( It safe to assume that i'm spoiled ) But, the four bangers power is waaaay lacking . On my 1980 toyota p/u , it had a 20r motor that seemed to have more power ! I'm way sorry for getting rid of that one ! But a growing family forced the sale.....
In third gear with the 20R i pulled a 18' dual axel trailer throught the Mohave desert & cahon pass . I passed a few D-100 dodges of the day , and so, i was impressed.
Okay, Next question !
How about adding a turbo / supercharger for more power ? I'm not looking for a Rocket ship , just about 30-40 " dependable " H.P. & 7-10 lbs. max boost .
Like i said ... I don't wanna blow the damn thing up but, will it hold the same MPG , Approxamently ???