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  #31 (permalink)  
Old 09-30-2013, 12:19 PM
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reread my first post

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  #32 (permalink)  
Old 09-30-2013, 01:13 PM
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what do you guys think should i do it?
Suit yourself. It's your time and your money.
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  #33 (permalink)  
Old 09-30-2013, 01:21 PM
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@ this point,you have a 50/50 chance that it is what he says.As I said earlier,just becuz he bought the parts & had machine work,doesn't mean squat if it wasn't put together rite.Did he crank it for you?I would @ the very least,hook up an oil psi guage & do a quik compression ck to see if all cylinders are producing good even psi.Shouldn't be that hard to do.If it was running ruff & he's blamin it on the wires,a cheap set @ Autozone for $30 will prove that out.It's a risk only you can decide if worth takin.You could get a good fresh 396,or,a bucket of trouble.
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  #34 (permalink)  
Old 09-30-2013, 04:19 PM
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Are you specifically shopping for a 396? If not,there are better choices comparitively priced & with a warranty of some sort.I'm not saying the 396 is a "BAD" motor,but,when compared to other Chevy engines,it did have a relatively short run for some reason.I don't think it lived up the expectations GM had hoped for.I've even heard,(& this is prolly some old wives tale)that the only reason the 402 came to be,was due to @ the time GM decided to pull the plug on the 396,they were sittin on a very large inventory of blocks rusting away that needed to be used up on something.The link I posted is representative of what I've seen price wise & does have a 12 month/Unlimited mile warranty for not much more.The 375 HP version specs the 292 cam that is spose to be in the motor your considering,so,we know 460 HP for this engine is not realistic.It does have an intake,carb,& distributor.Their condition tho is no better known than the engine tho.Your gonna get a few who will go out on a limb & say "Don't buy it",but'I don't think many who will say"Do It".
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  #35 (permalink)  
Old 09-30-2013, 05:00 PM
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it has the wrong heads on it. It has the low cr 396 2bbl truck heads on it.
They stink. The cr will only be 8.6:1 with the 396 2BBL motor "truck" heads on it.

you want the 396-325 or 350hp 98cc 100cc oval port heads. (10.25:1cr)
It will be a slug with the low cr truck head on it. Especially with that 292H cam.

The 2bbl 396 and the 325hp and 350hp 396's all had the same pistons w a small dome.
The difference was the cylinder head and intake manifold and compression ratio.
Ya it matters.
Look for a 454 or a 427

Last edited by F-BIRD'88; 09-30-2013 at 05:07 PM.
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  #36 (permalink)  
Old 09-30-2013, 05:03 PM
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The real reason for the demise of the 396 was the odd bore size. John D. was trying to cut down massive inventories of odd ball parts and consolidate. Several GM engines used 4.120-4.125" ring sets and Chevrolet got the word to more or less standardize.. The motor died shortly after because of the drastic lowering of compressions across the GM line in 71. A low compression 396-402 is just a gas eatin, emission spewing, TURD....
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Old 09-30-2013, 05:20 PM
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Or offer $1500 knowing full well that to get high performance (460 ish HP) from this motor you will need to swap the cylinder heads. (And maybe more)

If this engine had the right oval port heads and the right re work on the heads (porting etc) it would be capable
of making 460hp with that cam and the rpm intake manifold.

If the pistons are "stock" you can also assume they are not new. They are probabily re- used.
Theis may be a decent rebuild (even if the stock pistons were re used) or it may be junk.
It sure has the WRONG HEADS ON IT.

I would take a bore scoop with me to inspect...or pass..If the seller will not allow pan and head removal to inspect. a 454 is a LOT BETTER a 427 is a LOT BETTER.
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  #38 (permalink)  
Old 10-03-2013, 02:19 PM
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You guys are gonna hate me for this but it appears i gave you guys the wrong casting numbers for the heads DX i have since passed on the deal and he has posted all the casting numbers with pictures of the it seems that it was an L35 out of a 1969 chevelle
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  #39 (permalink)  
Old 10-03-2013, 02:50 PM
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The 3931063 heads listed in teh ad are very decent closed chamber oval ports
original 1969 427 390HP. With proper prep and some porting this engine could easily create 460HP with headers. The actual chamber volume varies a bit. 101cc to 104cc ish
Its one of the good ones.
it is likely these heads do not have any porting done...so....

The comp 292H cam needs a stiff gear and 10" 3500 stall. It has a very rough idle
Needs a agreeive distributor recurve ith lots of inital timing at idle. Some people simply lock out the timing curve for this one.
But makes very good mid and upper power with then right valve springs.

Be sure the pistons have a small dome on them as a flat top replacement 396-402 piston will result in a low compression ratio.
Correct compression ratio on non decked BBC's is established when using a fatory like .022" shim gasket.
A .040" replacement will result in lower cr, depending on the block deck height.
if you want to get 460hp from it this kind of details matter. But the potential is there.

Last edited by F-BIRD'88; 10-03-2013 at 02:55 PM.
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  #40 (permalink)  
Old 10-03-2013, 02:55 PM
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oh wow that's good. it did have dome top pistons he took the heads off and showed me i just had to pay him for new intake gasket when he did take them off now i couldn't tell if it was a small dome or large dome since im no expert in that subject and i used a compression tester and it had 150 psi in all cylinders. i tried getting back in touch with him but i haven't been able to hes probably not wanting to sell it to me anymore since i wasted his time i do hope he gets to sell it though it would be a shame for it to just sit there while hes away in the army
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  #41 (permalink)  
Old 10-03-2013, 03:12 PM
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There is a crappy very small dome .125" small dome reduced compression height rebuilder piston used in these motors
for cheap rebuilds. You want to avoid this if you really want power.
Speedpro sealed power cheapy plain cast replacement 402P. results in a low cr and modified piston pin height.
You don't want this one.
When a 396 is built correctly they make very good power.

But a 427 or 454 done right is always more powerfull.

The 396 piston you want has a 17 to 24cc dome (about 1/4") (396 325 to 350hp 10.25:1
They should sit .022 to .025" down the bore at TDC on a non decked 396-402 block.

Getting 460hp out of a oval port 396 is all about the details.
The pistons should have had the part number stamped right on the top.
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  #42 (permalink)  
Old 10-03-2013, 03:21 PM
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they did sit down .24 in the bore at tdc if i remeber correctly when he showed me
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  #43 (permalink)  
Old 10-03-2013, 03:55 PM
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Quote:
Originally Posted by 1979 TA View Post
they did sit down .24 in the bore at tdc if i remeber correctly when he showed me
What you wrote is two hundred and forty thousandths (almost a quarter of an inch). Writing twenty four thousandths goes like this..... 0.024"
I'm not meaning to be snotty, but someone has to teach you guys how to write math.
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  #44 (permalink)  
Old 10-03-2013, 03:59 PM
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they did sit down .24 in the bore at tdc if i remeber correctly when he showed me
.024" not .24"

Did they have a aprox 1/4" dome height?
The crappy ones have a tiny .125" dome (+5.5CC)
and two universal style opposing intake valve reliefs.
( meaning the piston can go in either way.)

These crappy "rebuider" style piston with the opposing valve reliefs
and small .125" dome are the ones to avoid if compression ratio and actual power matters to you.


Usually stamped 402P30

results in non stock lower than stock compression ratio and a big hit on engine power.

The comp 292H Magnum cam needs 10:1cr+ but not more than 11:1 for pump gas.

The real measured compression ratio of this engine could be as low as 8.00:1

Last edited by F-BIRD'88; 10-03-2013 at 04:28 PM.
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