In my opinion 86-89 MAF are the best years for tuned port. The 85 and 86 lower intake manifolds fit the older style small block heads.
Ive done this conversion several times and highly recommend it.
I use an 87 TPI setup on my rig. Try to find a donor car or as complete a setup as you can. The small parts and sensors can nickle and dime you to death.
These guys stock almost everything for tuned port. http://stores.ebay.com/TPI-PARTS
I prefer the MAF style. Its more forgiving with a modified engine, within reason, than the speed density style. The mass airflow sensor can adjust within about ten percent to compensate for headers and even a mild cam. Stock 89-92 speed density cannot. Reduced vacuum causes problems with a factory map sensor and ECM.
If you run an aftermarket programmable ECM than speed density is the way to go. But if you want to use GM parts its MAF all the way.
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