Inliners International Forums General Discussion Engines piston choices for 250 engine rebuild

Hello, I am a newcomer to the online forum, though I have been a long time II member (# 057).

I am looking at rebuilding a 250 that has considerable cylinder wear. The engine is intended for a '37 Chevy coupe that I am building as a mild street rod driver. I would like to boost the horsepower a bit and raising compression is one thing that would help. My goal is to emphasize low end torque over high end power.

It appears SBC 307 pistons can be used in this engine, but not sure if the compression will raise enough to bother and I am concerned about the V8 wrist pin offset in an inline engine.

Your thoughts would be appreciated.

Hi Ray . . . welcome to the forums.

The use of 307 slugs in a 250 has been discussed quite a bit here in the past - though not much recently. The slugs are the same diameter as those from a 250 but are absent the characteristic I6 dish so they raise the compression ratio.

Given that your engine's bores are 'worn out' you are likely into a heavy over bore get them back to round and square to the deck.

Do you have a set of oversized 307's in hand? If not a custom built set from Ross or Venolia might be an easier option. The block can be bored to 'whatever' is needed to make it right and then the slugs can be forged to fit - complete with zero deck height.

regards,
stock49

I've found AutoTec/RaceTec to be more accommodating in making piston forgings that fit your needs. They also will work with Total Seal to come up with ring combinations that meet your EXACT needs.

Nice folks and prices are reasonable too.