340 pistons in a 360

[danmax]

I've just pulled the sump off an older built but as new 360 I have here and the part numbers on the pistons are 2899479 - which are 340 pistons?

Was this common practice and guesstimates please on what sort of comp I'd be looking at with standard j heads.

Logic tells me the pistons would be too tall to work and would require a fair bit of machining but thats what is there in front of me.

 

[RustyRatRod]

I think Tom Hoover was the first to do that. It was a common practice to get compression up in the 360 before high compression pistons were made for it.

 

[danmax]

Ok cool but I would assume they'd need a bit of work to fit?

 

[RustyRatRod]

I guess. I don't know the exact recipe.

 

[Abodybomber]

I guess. I don't know the exact recipe.

Was a 1972,73 article,Hot Rod,I.I.R.C.... Hoover dropped cast 340 slugs, milled the difference. With today's labor cost's,gains would kill you.If you have access to a machine shop & a balancer,this could be feasable.

 

[doug 371]

my friend put 340 pistons in mine...he milled the tops had valve reliefs redone and he did a lot of work on the skirts

 

[danmax]

And what sort of comp did u end up with?

 

[Locomotion]

Here is an archived thread on the subject.

http://www.forabodiesonly.com/mopar/archive/index.php/t-188119.html

 

[Abodybomber]

Thanks ,Locomotion...

 

[danmax]

Thanks for the link - that thread explains a lot

 

[skrews]

With the number of 360 pistons out there it would be silly to use the modified 340 pistons this day and age.

 

[bad440]

Seen it done.but the poster above is right.

 

[RustyRatRod]

All true, but 40 years ago it was a good idea.

 

[Abodybomber]

Seen it done.but the poster above is right.[/

Yes.

 

[danmax]

Well finally got this thing running after 6 years sitting in my garage... and it is a really sweet engine. runs really well on pump gas 34 degrees total timing.

 

[rumblefish360]

EXCELLENT!!!!

I know all to well about long delays! Truly it sucks but that’s the way the ball bounces sometimes. At least you stuck with it and seen it through.

Tell us about the final build!(pictures perhaps?!?!)

 

[j par]

They want to start and run. Last weekend I helped a guy start his 260 Ford. It's in a 63 Fairlane. He had it rebuilt 23 years ago and the first five years once a year he would run a drill in the oil pump. We fired it off and broke it in no problem LOL..
They want to run....