1968 427 840 heads
Race Director
Joined: Jul 2015
Posts: 13,082
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From: SW Florida.
i don't think so. this is a closed chamber rectangle port head. 148 is semi-open oval small valves. the 10 cc smaller chamber will raise CR quite a bit and the rectangle ports will require a different intake manifold. and the chamber edge around the bathtub will probably hit the piston. and this is a collectable head. grinding the chambers to clear the pistons will break some SS386 owner's heart. others will weigh in.
Safety Car
Joined: May 2001
Posts: 4,759
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From: Fairfax Virginia
I have a 427 in my 1968 where I built a L88 replica using a pair of GM Part # 3931063 heads which are Closed Chamber heads made for our 1968 427's. I am not sure about the pistons but I have a set of L88 pistons in mine and the engine runs 12.25-1 Compression ratio which is what I was shooting for. I understand they used these heads with other pistons in lower compression engine configurations. The Valve Pockets on the pistons I have stick above the block when at TDC and mesh perfectly with the heads. I have a whopping .125" of clearance between the pistons and the heads when at TDC which works for me in this configuration.
Try and stick with closed chamber heads as they were stock in 1968 and they are really good at resisting detonation or pinging. I had mine completely rebuilt with all new parts along with hardened exhaust seats to handle the unleaded fuels used today. They are not that expensive if you start hunting for them. I found a good set at Corvettes@Carlisle for a couple hundred dollars and they even came with casting dates that are appropriate for my early 1968. The other choice is buying a set of aluminum heads but most of those are open chamber or semi-open chamber for cleaner emissions. When I built this engine the aluminum BB heads were several thousand dollars each and a bit out of reach for me at the time.
Best regards,
Chris
P.S. Welcome to the Corvette Forum! We are glad you are here as this is THE place to be with Corvette questions!
Try and stick with closed chamber heads as they were stock in 1968 and they are really good at resisting detonation or pinging. I had mine completely rebuilt with all new parts along with hardened exhaust seats to handle the unleaded fuels used today. They are not that expensive if you start hunting for them. I found a good set at Corvettes@Carlisle for a couple hundred dollars and they even came with casting dates that are appropriate for my early 1968. The other choice is buying a set of aluminum heads but most of those are open chamber or semi-open chamber for cleaner emissions. When I built this engine the aluminum BB heads were several thousand dollars each and a bit out of reach for me at the time.
Best regards,
Chris
P.S. Welcome to the Corvette Forum! We are glad you are here as this is THE place to be with Corvette questions!
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
the problem is the 2300 pistons are open chamber small valve relief pistons. they will probably hit the edge of the bathtub and the 2.19 valves may hit outside of the valve reliefs. 427 Hotrod knows this setup. he will weigh in.
