307 Pistons in 250 L6

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old28

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Joined
Aug 22, 2009
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681
Location
Camarillo, Ca
Has anyone out there installed a Chevy 307 FT piston in a Chevy 250 L6 motor? I know it is an easy change to up the CR.

I am looking for someone that may have done one and I would like to find out if they think it was a good move.

Also does anyone know if you can get forged 307 pistons & were without having them custom made? All I can find are cast.:confused:
 
Has anyone out there installed a Chevy 307 FT piston in a Chevy 250 L6 motor? I know it is an easy change to up the CR.

I am looking for someone that may have done one and I would like to find out if they think it was a good move.

Also does anyone know if you can get forged 307 pistons & were without having them custom made? All I can find are cast.:confused:

Im looking for the same answers to your post. Did you find out anything?

Jim
 
307 is a 283 bore and a 327 stroke. 250 has a 283 bore but the stroke is 3.53 (according to Wiki), not the 3.25 of a 327 (307)
I think what you need to research is the piston compression height on both pistons to see if they would be compatible
 
Sorry I have not been on RRR for a while. I have been making some modifications to my SDRA Vintage 6 cylinder dragster to get it ready for the 2013 season.:rolleyes:

Maybe I can add a little more information to this thread for all to read and comment on. First off I have Leo's Second addition and have read it front to back a few times, real good and all 6 cylinder guys should have a copy.;)

The 307 FT pistons in a 250 motor with a normal 3.53 stroke with it's 1.655 CH will put the piston .020 down in the hole and leave .015 to mill off the block for a -0- deck. Normal 250 pistons are .035-.042 in the hole. Installing these pistons by their self will increase CR to about 9.5/1, if you mill the block for -0- deck you will get around 10.0/1 and with 72-74 CC heads milled .060 you get about 10.5/1CR. It is a cheap way to raise CR without buying custom pistons for 500-600 dollars.

My main reason for asking about them is I can only find them as cast pistons and would like to run forged FT pistons if I can. The 256" motor I am going to build for this season will make around 280-295 HP and turn 6800-7000 RPM on the 1/4 mile top end.

Hope we get more feedback on the pistons.
 

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It's Called "EGO!!!!!"

I've built a lot of SBC & BBC in my 45 year drag racing game, but this is my first inline 6 and I still have a lot to learn about old school combinations.
 
Come on guys, someone out there has got to have tryed this piston swap in a Chevy 250 L6 engine.[S

Let me know the in & out of this combination.:rolleyes:
 
yes i have read about it several times, but haven't done it myself. i think several times on inliners board several years ago, also on the stovebolt site. i have yet to get Leo's second book but i have 3 copies of his first. i thought it was suposed to be a pretty straight foward swap. 250 con rods/ 307 pistons.
 
Hoggyrubber -- Ya it is more or less a straight forward deal as fare as I can tell, just was looking for someone that had done it. May check on inliner board to see if someone over there has done one.;)

Leo's Second edition is great reading and has tons of good information, read it more than once. Lot of high dollar stuff, but not much home brew hot rod information.:rolleyes:
 
i do remember several post on it thru the years. i haven't been on the inliners board in prob 6 years or so. my password stopped working so i never tried to post anymore and haven't even looked in in a while. i know i saw several post on the stovebolt forum too. i want to get that second book sometime.
 
Thats the best reading a 6 cylinder guy can do, pick one up, tons of excellent information.

I signed up on Inliners so I will post something tonight and see what they have to say.
 
If anyone has made any progress here , please post a reply .

I want to build the same engine for my 50 Chevy truck . Some details would be nice to know .

Thx ,
Gonzo
 

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