"Keep in mind that you need an intake that will bolt to your cylinder heads. The bolt pattern changed in 87, so if you have 86 or earlier heads, you need an 85 or 86 manifold base. The four center bolt holes are angled differently on the 87-92 intakes. A stock TPI intake with not work with Vortec, or LT1 heads. However, you can run TPI on Vortec heads if you use an aftermarket intake manifold from Scoggin Dickey. "
http://tpiparts.net/installing_tpi_on_your_vehicle
I can go on & on, providing off site links, proving me right.