SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: beerjet on June 18, 2014, 11:21:16 PM

Title: Preferred stock Chevy cylinder heads.
Post by: beerjet on June 18, 2014, 11:21:16 PM

Which ones and what are the advantages to one over three others.

-beerjet-

Title: Re: Preferred stock Chevy cylinder heads.
Post by: mash on it on June 18, 2014, 11:33:04 PM

Which way ya going?
piston to match heads ...
or
heads to match pistons?

Dan'l

Title: Re: Preferred stock Chevy cylinder heads.
Post by: beerjet on June 18, 2014, 11:39:36 PM

Quote from: mash on it on June 18, 2014, 11:33:04 PM

Which way ya going?
piston to match heads ...
or
heads to match pistons?

Dan'l

In general really.

-beerjet-

Title: Re: Preferred stock Chevy cylinder heads.
Post by: mash on it on June 19, 2014, 12:01:52 AM

781/049's... big chambers, small valves...118-122 cc's
990's big chambers, can have small valves, or 2.19's...119-122cc's
Dozens of other BBC heads out there.
I run 427 heads, 2.06's, 100 cc's, HONEST 9:1 comp ratio, w/ flat top pistons, not great for 6K+ rpm, I'm at 4900 r's
W/ 781's, Id be at 8.1 c/r, I'd loose 50+ HP, or more

Where ya startin' and where ya goin'?

Dan'l

Title: Re: Preferred stock Chevy cylinder heads.
Post by: Marcsrollin on June 19, 2014, 12:24:55 AM

casting number, 3904392
engine they came on, 427
year, 1967
valve sizes, 2.19/1.88
106cc L-88/L-89 Aluminum Rectangular port

Title: Re: Preferred stock Chevy cylinder heads.
Post by: ka0tyk on June 19, 2014, 12:56:43 AM

is the only casting number on the inside of the head?  i dont want to have to remove my exhaust just so i can pull a valve cover to see what heads i have.  the only mark i can find on the outside is on the passenger head at the rear.  "6318" and a "1"

Title: Re: Preferred stock Chevy cylinder heads.
Post by: 1975_Challenger_461 on June 19, 2014, 01:00:17 AM

Gotta remove valve covers bro. I have the 049's and love them!

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Title: Re: Preferred stock Chevy cylinder heads.
Post by: ka0tyk on June 19, 2014, 01:12:52 AM

damn this is the only pic i have of the inside... next time i have the motor out i guess ill take a peek.  block is 3999289 but i guess the heads could be anything...

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