1. Bigport 4AGE's (AE86, AE82, AW11), and possibly the early early model GZE AW11 (although i've never seen them).
2. Bigport 4AGE's have smaller rod journals --- but smallport 4AGE's, all GZE's (except that possible early GZE), silvertop 20V, blacktop 20V are the same.
3. Yes they will.
4. Yes they are - useable with all of the cranks as mentioned in "2."
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If you are looking at getting rid of the 3-rib block, and want to rebuild it, just buy ANY 7-rib block that's in good condition. There are three different rod sizes with the 7-ribs - The biggest come in the AE92 4AGE, and AE92 4AGZE. The middle-sized rod comes in AE101 20V and AE101 4AGZE. The skinniest rods are just in a AE111 20V.