68' 430 into my 66' Chevy C10 short bed

First off I'd like to say hello I'm a new member. After reading just a couple forums it was a easy decision for me to make. Yeah fellas like the post reads I'm dropping a 1968 430 into my 1966 Chevy C10. I mean why not right? The truck needed a power plant and I love out of the norm things that turns heads and in this case my rear wheels too! I got a hell of a deal on the 430 with the stock TH400 bolted to it. I'm mainly curious if anyone's done a similar engine swap that has any advice for me or things I need to look out for or change? Any advice would be highly appreciated. Another thing I've read into is that these engines came stock with 10.25:1 compression ratio? That doesn't sound very street friendly on pump gas. Are there certain mods or different 400 or 455 heads I can swap on this thing to make it less likely to detonate? Any advice would be highly appreciated. Oh by the way I'm a regular working class guy who has kids so TA performance is out of the question I wouldn't even feel right spending that kind of money for parts on a hobby. Thanks again!
I would not be afraid of 10.25:1 compression. If the engine is in good condition it will run just fine on premium. Pinging problems may occur if the timing is advanced too far, or, and more likely, if the timing chain is stretched too far causing late cam timing.
Thank you for your response Bob! You answered a big what if, that I was worried about! Mainly I just let a couple of "wannabe mechanics" get in my head and rain on my parade. As for the condition of the engine from what I was told is that it ran like a top but I'm going to do a compression test followed by a leak down test on it tomorrow. The factory timing cover has some corrosion where the radiator hose slides on so after I do those tests I'm going to pull it off and order a new one from summit I already planned on ordering a new timing chain set too. Might as well right cheap insurance also a water pump and upgrade the oil pump too. Can you tell me what the best carburetor is out there to run on these things?
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One way to look at the question is from the octane requirements then vs fuels available today. The shop manual shows the 430 4bbl needs 90 octane as tested by the Motor method or 99 as tested by the Research method. Modern gas pumps show the octane as the average of the Motor and Research methods (R+M)/2. So the average octane figure from the shop manual requirements is 94.5. This is only 1.5 points above typical premium pump gas (93) presently available.

The original metallic head gaskets (GM no 1384411) were .020" thick. Many times these gaskets were replaced with composite gaskets (GM no 1384094) which are .045" thick. The thicker gaskets lower the compression ratio and the octane requirements.

The factory started installing the composite gaskets late in the '68 model year. Attached is the Dealer Service Bulletin 60-14 which shows which engine date codes have the composite head gaskets. If your heads have ever been removed, the replacement gaskets are likely composites.

Also attached is another '68 bulletin 60-5 on operating the cars on lower octane fuel. By using the thicker head gaskets and different distributor springs, the 430 was rated to run on gas as low as 82 octane (by today's avg rating number).

Hopefully it won't knock on even today's 87 regular octane.


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