1968 c10 396

[68Gold/white]

I believe the head number is visible, by taking off the valve cover, like most small block stuff. Do that first...

[mike's1965]

Originally Posted by 68Gold/white

I believe the head number is visible, by taking off the valve cover, like most small block stuff. Do that first...

I'll do that, besides the passenger side valve cover gasket is leaking anyways.

Bought some Summit racing brand valve cover gaskets for BBC that are supposed to last longer and be able to be pulled on and put back on over and over.

Guess the sitting of the engine made the fel pro valve cover gasket go bad.

Will also buy the scope camera, been wanting it anyways.

[geezer#99]

First bbc I rebuilt was a 67 396 265 hp 2bbl 9 to 1 motor. Pulled it in October and rebuilt it over the winter in my wooden floored 10x10 garden shed.
Basic refresh. New rings, bearings, cam and lifters. Put in a hydraulic cam with similar specs to this cam.

https://www.jegs.com/i/Crane-Cams/271/969961/10002/-1

Heads were already done.
Worked well. Would chirp the hides into 3rd. Speed shift at 6 grand.
Ran headers, performer rpm and Holley 750 vs carb.
Timed at 18 initial, 16 mechanical and 12 vacuum.
Lived at 3500 foot elevation so no problem with aggressive timing.
Ran in a 70 chevelle ss with m21 and 3.31 gear.
Sure wish I had that car still. Along with the other iron I had.

[mike's1965]

3935401 are the head numbers.

[geezer#99]

Check on this list for that number.

https://www.mortec.com/bbc.htm

[Mike C]

That casting number is for an open chamber tall deck 427 head from 68-76. If an original 68 396, that head may be killing your compression ratio. I did not find out what cc the head was, but the closed chamber heads would have been on the 68 motor.

My 69 L36 390/427 has 100cc chamber heads for 11:1 compression. If the factory 396 heads were 100cc with 9:1 compression then the 401 casting head would make for 8:1 compression if it is 110cc.

You need to do more research and figure out exactly what mashup of parts you have.

[Steeveedee]

I bought a scope so that I could look at the bore of my rifle. That would work, too. It plugs into a lap top or cell phone, so it doesn't have that camera head on it. That's an excellent alternative to pulling a head off!

[68Gold/white]

Originally Posted by Mike C

That casting number is for an open chamber tall deck 427 head from 68-76. If an original 68 396, that head may be killing your compression ratio. I did not find out what cc the head was, but the closed chamber heads would have been on the 68 motor.

My 69 L36 390/427 has 100cc chamber heads for 11:1 compression. If the factory 396 heads were 100cc with 9:1 compression then the 401 casting head would make for 8:1 compression if it is 110cc.

You need to do more research and figure out exactly what mashup of parts you have.

AND look into the cylinder to see if you have flat top, dished or domed pistons!!!

[mike's1965]

I'll buy a scope to see.

Who knows what's been done to this engine before I got it, I remember buying the 1974 Chevy truck in February 2003 to get the engine (assumed 454 since that's what emissions/tune up sticker above radiator said) the TH400, and power steering and disc brakes parts.

Possible the 454 blew up or wore out and the previous owner of the 1974 Chevy truck got this engine from a salvage yard.

Could it be possible GM put these heads on the truck 396 from the factory?

[geezer#99]

You got a pic of your motor?
Mainly from the front looking at the head and block.
Visual clues!

[mike's1965]

I found a picture from years ago with engine ready to go into truck.

Do I need a picture hosting site to get it here, I see logo with mountain and sun that says enter URL, is there another way to attach it?

[mike's1965]

Engine picture

[68Gold/white]

I like the Cool Whip carb cap!!!

[mike's1965]

Originally Posted by 68Gold/white

I like the Cool Whip carb cap!!!

Haha I, must have did that to keep dust out of carb.

By the way I painted it that blue since it almost is a perfect match for the blue on the truck, almost everyone says I should have gone Chevy orange.

I'll try to get more pics soon.

[RustyBucket]

Have you checked the deck stamp in front of the pass. side head? The 3 letter suffix code will usually I.D. the origin of the block pretty well. Hopefully the block hasn't been decked.

My 2wd Blazer has a .40 over 454, #236 peanut port heads, Perf. RPM intake, 3310 Holley, mild CamDynamics hyd. cam, long tube headers. It's LOW compression & runs fine on 87oct. TKO 500 trans & a 3.07 open rear. Kills the R. rear in first but hooks up goes pretty good after. Never had it to the track but the previous owner had time slips for mid 14's @ 95mph. Said he was on the Power Tour 500mi. from home so it was an easy pass.

[mike's1965]

Originally Posted by RustyBucket

Have you checked the deck stamp in front of the pass. side head? The 3 letter suffix code will usually I.D. the origin of the block pretty well. Hopefully the block hasn't been decked.

My 2wd Blazer has a .40 over 454, #236 peanut port heads, Perf. RPM intake, 3310 Holley, mild CamDynamics hyd. cam, long tube headers. It's LOW compression & runs fine on 87oct. TKO 500 trans & a 3.07 open rear. Kills the R. rear in first but hooks up goes pretty good after. Never had it to the track but the previous owner had time slips for mid 14's @ 95mph. Said he was on the Power Tour 500mi. from home so it was an easy pass.

Yes, about 10 years ago, I remember XE something and that's how I found out it was a 1968 396, I remember removing alternator bracket and swinging alternator out of way, will have to see if I can find it.

[mike's1965]

"moved the alternator out of the way and used some carb cleaner and a rag to wipe off the pad.

The 3rd mark from left might be a 1 or I, it's blurry.
Looks like T0101XE
or
T0I01XE"

This is what I posted over 10 years ago on another forum.

[mike's1965]

Went to harbor freight, the inspection camera for 80 bucks was gone, have a 20 percent off coupon, have to try another store.

I did buy an electric ratchet called earthquake, they wouldn't let me use the coupon on it saying it's already on sale at $99.99, at first I told them nevermind but the manager said it's actually a good deal at $99.99 so I bought it.

Drove the truck about 11 pm, and it does run really good, I'm thinking the Edelbrock fuel injection will make it even better as well as the summit coated headers.

I'll try other places for inspection camera and report back.

[mike's1965]

#1 cylinder and #2 cylinder, the Milwaukee inspection camera is ok, but could only get the upper side of pistons because the angle of spark plug hole and cylinder wall.

They look at least like flat top, but it also looks like in the middle it starts rising up.

[geezer#99]

Originally Posted by mike's1965

"moved the alternator out of the way and used some carb cleaner and a rag to wipe off the pad.

The 3rd mark from left might be a 1 or I, it's blurry.
Looks like T0101XE
or
T0I01XE"

This is what I posted over 10 years ago on another forum.

T is Tonawanda.
0101 is built on January 1st.
XE is 1968 310 hp 396 truck.

https://nastyz28.com/gm-chevy-codes/...-suffix-15.php

[geezer#99]

IIRC pistons should be flat on one side with a small dome on the other.

[mike's1965]

That's pretty cool about the engine where and when it was built.

[mike's1965]

I was pretty disappointed in the Milwaukee scope, but found attachments to buy for it, a mirror, magnet, and hook kit, ordered online through Amazon as Home Depot doesn't sell it, yet they sell the scope camera.

Tried mirror in #1 cylinder tonight and I could see more of piston, but it wasn't very clear, so didn't try to get a picture.

[mike's1965]

I'm wondering if adding better heads (unless my head's are already good?) either factory iron heads with new valve job or maybe new Edelbrock 100cc aluminum heads, and a cam
would step this engine up.

Saw a video of a 396 with mutha thumper can that sounded great, but read they are only for sound and don't perform that great compared to other options.

[weq92f]

Originally Posted by mike's1965

I'm wondering if adding better heads (unless my head's are already good?) either factory iron heads with new valve job or maybe new Edelbrock 100cc aluminum heads, and a cam
would step this engine up.

Fairly recently, I had a set of #063 heads worked at a shop with 3 angle valve job, new SS valves, dual springs, guides, seals, retainers and keepers ( stock valve sizes ). All in it was just under 1400. This was with me bringing in the heads.

Now I don't know what those Edelbrock heads cost but the comparison is healthy! Especially given the weight of the iron ones.

Hth,

-klb