Hey guys I've seen a lot of posts about swapping a 12a with a 13b but all keep mentioning the 13b from an fc is there anything I'll need to modify if it take it from an 84 gsl see or is it direct swap I have an 81 gsl and I'm wondering what I need to rip out of the 84 do I need the entire harness including interior or just engine harness also will it just drop in and bolt to my subframe or do I need the 84 subframe as well?

 

For a stock installation, you would need every sensor and bit under the hood including wiring harness. You also need the sub-frame (cross member that goes from frame rail to frame rail). Might as well just swap the entire sub frame including shock towers and steering. This can be taken out as an assembly and just replace the 1981 one. Then get the 1984 rear end and do that same. You would also need the cluster and dash wiring harness. The 1984 cluster will not fit the 1981 dash so that is a challenge. I'd just swap out the entire dash. If you swap the dash, the shifter hole will not line up so there is some more work there.

Sounds like a lot of work but can be done. Might be easier just to find a GSL-SE that is already sorted and avoid all the work.

 

If you carb it, could you just do the motor/subframe? (I have no idea, just asking)

 

If its carbed you just have to dremel out the motor mount to accept a longer engine. And obviously the headers have to change.