it would also help a lot to know what year 3100 you are talking about, 2000 + heads are better from the factory.
If you want to get real crazy, you can do what I plan on, run fiero 2.8 pistons with 3100 heads. Very high compression, like 11.5-12.5. I plan on using a 3100 block/heads/intake and fiero crank, rods and pistons. The other good thing about 3100's is the fact you can get a custom cam ground for it.
You can also get on 60degreev6.com to find more info about the engines themselves.
-Brandon
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The List;
1) 98 Jetta TDI (55+ MPG) 2) 95 BMW 325i 5 spd (Wife's car) 3) 82 Chevy Scottsdale 6.2 (tow duty)
4) 87 Fiero 3800 S1 S/C 5spd (almost road ready) 5) 85 S10 diesel 5spd (engine donor) 6) 84 S10 (receiver) 7) 84 S10 2.5 5spd (parts)
8) 87 GMC S15 2.8 5spd parts truck 9) 91 Mercedes 190E (diesel 5spd swap) 10) 84 Mercedes 190D (donor) 11) 85 Fiero (parts)
12) 85 Fiero SE (7730 ecm, 3500) 13) 87 GT (7730 ecm, hybrid 2800, izusu 5spd swap soon)