3rdcoastpowersports

GM Marine Big Block Cylinder Head P/N 19256827

Looking for Intake runner CC size, Combustion chamber size and Max lift cam lift the springs will support...

I just got off the phone with GM directly and they had no other information available other than what I could readily find online.

Planning on putting these on a pair of brand new 489CI Gen 6 Big blocks that are going in the bilge of my 36' cabin cruiser so im looking for a set of head that produce alot of TORQUE at low rpms

Camalot

3rdcoastpowersports

Close Cooled. I thought the 19256827 was a large oval head, for some reason I was thinking it was a 269 or a 290cc intake runner and a 118cc chamber but I cant seem to find where I found that before.

Rookie

iTrader: (4)

Those heads are to the tall deck GM 488 multi-fuel generator engine. Vortec heads, small chambers, higher compression and oval port that comes on this engine.
https://www.jegs.com/i/Chevrolet-Per...28586/10002/-1

SB

iTrader: (1)

Those are the heads used on the 488cid Tall Deck GM motor right ? Appears so after quick diffing around.

If so , see here:
https://sdparts.com/i-24080510-gm-en...et-engine.html

And speaking of which, I would not be afraid to call them(Scoggin-Dickey) about more info on those as they are not ust a GMPP parts place. They buildmotors and other thing too. They have been around seemingly forever.

Rookie

iTrader: (4)

There's better heads out there...
P/N 19256827 2.06"/1.72" valves., 99cc

SB

iTrader: (1)

Yup, they definitely know this motor and cyl heads - which appear to be the L29 Vortec's.

They built a motor around this 488 long block.

See here:
https://sdparts.com/n-9418-sdpcs-198...ct-update.html

SB

iTrader: (1)

Sorry, I missed this. Would have saved me a lit of time see this post. LOL.

3rdcoastpowersports

Thank you
So they are tall deck heads and I have a std deck engine with pistons designed for 8.5 w/118 chambers.

So........
What heads do I buy for my boat (36' chris craft commander... think RV on the water) to put atop my two new Gen 6 489ci Big blocks.... I just want as much torque as possible. I do not ever plan to rev past 3800rpms.

Any and all advise is appreciated as im new to the big block platform.

dereknkathy

It doesn't matter tall deck or standard deck. They interchange. And does not look like a vortec combustion chamber. those are same chambers from 781 and 088 and virtually all open chambered heads. so it looks like these are updated 049-781 heads. which would actually be optimal for your build.