chev 305 engine repair

[mchris]

Hello all, have a question for the experts; have a 92 Caprice 305 TBI with expired engine, broken rod went thru oil pan and piston damaged valves in head; I have an older 305 engine code 'H' was carburated 4 barrel. What I am doing is trying to fit the TBI manifold on the older engine and heads, I have plugged, redrilled and ground to fit the middle four intake bolt holes so everything fits. Question: the 92 heads had the water passages capped on diagonal corners but the older heads did not. What is the purpose of these plugs? Are they to control the temp in the TBI intake or for the heads? Should I plug up the old heads when I reassemble? Thanks Mike

[DanD]

I think you’ll find that if you do not plug them you’ll not have much heat in the car. I believe they are capped to direct the flow of coolant and to cause some back pressure in the system so that the heater core is feed. The intake gasket set probably has the metal inserts that can be installed on the gasket.
Dan.