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well theres guys running 3400s with 3500 top ends, the only thing i could forsee being a problem is the valve size, if the 3.1 bore isnt physically large enough for the valves to fully open they'll just smack the block and bend
 

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valve sizes are the same as the 3400, the 3500 has a larger combustion chamber that overlaps the bore on a 3.1 block.. Ben says that you'd have to bore the 3.1 like .040" or more to get it to clear.

so yes.. they will physically bolt up but won't work on a stock bore. way better to use them on a 3400.
 

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whitelightning2 said:
valve sizes are the same as the 3400, the 3500 has a larger combustion chamber that overlaps the bore on a 3.1 block.. Ben says that you'd have to bore the 3.1 like .040" or more to get it to clear.

so yes.. they will physically bolt up but won't work on a stock bore. way better to use them on a 3400.
yea thats what i was getting at, just couldnt think of a good way to word it lol
 

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i'll have to ask him if .030" would clear. it would be interesting for my buddy 's engine.
 

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slimshady_10_80 said:
what about a 3500 block with 3400 heads topend etc
thats just a waste of time, your going to probably end up losing power, the 3500 top end flows better then the 3400 top end and you have all teh added extras of having to make new mounts and an external crank trigger
 

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I'd like to add, this is something you should test for yourself, i've learned the hard way to never trust everything you hear on the internet.

a 3.4 or 3400 headgasket fits the combustion chamber perfect, right up to the edge. Logically one would think that you'd need to bore the 3.1 out to a 3.4 (which can't be done).

here is a thread on 60degree where it was discussed...

http://60degreev6.com/showthread.php?t=35296
 

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whitelightning2 said:
I'd like to add, this is something you should test for yourself, i've learned the hard way to never trust everything you hear on the internet.

I think your right Dave, no ones tryed it, so who know :-? I would like to actually see someone try but then again for the price of 3400's why use a 3.1 block. If I had some 3500 heads kicking around I would actually try this combo. I would think if it works you could put out some good numbers but until someone trys we well not know :-?

Only thing that would bother me is the 3.1's poor oiling system but thats just my 2 cents.
 
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