I am trying to decide what to do engine wise in my 1968 convertible. I am restoring it right now and would like to improve performance of the engine while I have the fenders off and it's easy to remove. At this point I don't want to spend a ton of money as the resto is consuming most of the budget.
The car currently has a good running '69 YE 350 with 11 heads and guessing 254 cam, plain jane 265HP engine but I have put on a 4 bbl years ago.
I just stripped apart a stuck '74 455 with 4X heads and 067 cam, engine is fine but destroyed several pistons getting them out as they were rusted in place, block is fine, original bore, crank and cam are good also. Would need a complete rebuild and probably .030" overbore.
Now I have a lead on a good set of 093 heads which are the '66 389 closed chamber 1.96/1.66 68cc heads and are only a couple hours away. Since the 455 would need a complete rebuild, a good winter project, my thoughts are this and would appreciate some feedback whether this combo would work, or whether mixing 1966 heads with '74 cam and '69 350 is bad.
Using my 350, put in the 067 cam and 093 heads, should get me somewhere around 9.5:1 CR and the 067 is a decent cam. I would guess power would be around 300-320 HP. It would be an easy upgrade for little $$$.
Your thoughts? Are the one year 093 heads good or should I hold out for newer ones from say 67-73 or so, open chamber etc.?
Ok since you asked here my thought. You say the 350 ran good the way it is/was so if I were you I would put it back n and be happy with a nice cruising machine. Meanwhile if you want more power instead of picking and piecing some Frankenstein motor that ultimately will have a disappointing outcome you could build the 455 right as time and money allow and swap it in when it's finished. Just my $.04.
Those heads will work real nice on the 350 better than the 11s as they have same valve size but smaller chambers and screw in studs. I'm not sure about the details of the pre 67 heads but there are some details due to valve angle that may limit cam choice and lift. Not a good option on the 455 at all.
