Hi

I am swapping a 73 model 400 sbc into a 92RS. The cylinder heads do not have the neccessary accessory holes to hook up the factory a/c. Any suggestions other then buying /swapping out new heads?


Thanks!

 

Buy/swap out the heads. There are no alternatives. If there were, somebody would have figured it out sometime in the last 35 years since the heads with bolt holes came out, and those old heads wouldn't be quite as worthless now as they really are.

Those aren't the heads off of a 73 anything, least of all off of a 400. They're off a 60s motor of some sort.

 

either the heads have been swaped or you don't have a 400, all 400s shoukld, or would, have the holes for accessories. you need new heads that have the holes.

 

the motor is a 400. it has been rebuilt by us already once. We had it in a 73 camaro without air but need heads that will adapt to a/c. The motor is a 73 model in which the air was on the drivers side. The a/c is on the passenger side in the 92; therefore, we dont have the capability to mount it. There is only the one hole that used to house the alternator (1973). Is there an aftermerket bracket that can be used on the heads for the conversion or would a GM head (ex. 350) that could have the steam holes drilled, etc. work with the 400 ? Thanks!

 

the casting numbers off of the heads match up to a 400. We pulled the motor out of an original 73 caprice. Thanks!

 

Did the RS have a 350? You might be able to swap in the stock RS heads provided they are 350 heads and they are 76cc combustion chambers. If you are that lucky, then all you have to do is have your steam holes drilled in the RS heads. Most machine shops can do this for about $50. If the RS had a 305, your out of luck. 305's had a 58cc chamber which is way too small for a 400 with stock pistons. REGARDLESS OF WHAT HEADS YOU USE, MAKE SURE YOU HAVE STEAM HOLES!!!

 

thanks wes...

Actually its my friends car and it came with the 305... What you said about the 350 heads would be the best thing. I told him that but he wasnt sure so thats why I posted for him. I bnelieve its the best way and I have a set of 350 heads that can be modified for his 400 and added. Thanks again!!!!!