Bolt hole pattern on the front of the heads

[dsteelejr]

I have an ‘88 K5 that is 100% stock with 276k miles on the original TBI 350. I’m going to be replacing that 350 with a SBC 400 with an Edelbrock top end kit and Pro Flo 4. The Blazer still has working A/C and I want to keep it working after the swap. I have a set of Edelbrock 5089 heads, which are for ‘86 and older. I’m trying to find out if the bolt pattern on the front of the ‘86 and older heads is the same as the TBI heads so I can bolt up the existing A/C compressor and alternator brackets on the pre-TBI heads.

 

[legopnuematic]

All small block heads with accessory holes should be the same pattern, late 60s to vortec era.

The 1986 and older is likely from being a perimeter bolt valve cover and not center bolt like the TBI and later valve covers.