Hot Rod Forum banner

396 build up

4K views 38 replies 7 participants last post by  techinspector1 
#1 ·
I was thinking about buying a big block 402 and I saw one on Craigslist for 3k fully rebuilt with a bunch new parts he said he hasn't dynoed it but it should make 460 horsepower I was wondering is this a good buy for the price and is the horsepower numbers in the right spot for what it has in it here's the link as well
402 BB chevy ($3000 O.B.O)
 
#8 ·
" could mean it is just a dolled up motor on a stand that has issues."

My exact thoughts.
I have bought literally hundreds of engines.
Most of the parts listed are stock GM stuff.
With a used set of covers and an aftermkt intake...Beware.. As stated all 396-402 used a dome piston and the truck heads don't support the claimed horsepower.
 
#9 ·
I would @ the very least ask for parts reciepts & a copy of the shop invoice for the stated machine work.Then you could @ the very least call up the shop & ask them about the work performed.If he can't produce any of that or @ least the shop # & contact,I think I would pass on it.If it is indeed a fresh engine,I'd say it's a good deal.
 
#10 ·
I have done that as well he has the receipts and documents to prove his statements and I called the machine shop owner and the work done on it is true as the receipts state and the machine shop states so the only thing I'm concerned with now is that I'm pretty sure the HP is not even near 460 I don't really need that much anyways i just at least want 400 to 450 you guys think it can be near those numbers then?
 
#13 ·
From what I've been told the engine was stock at 350 HP before being upgraded but what determines how much HP it had while stock because there were like 3 or 4 different 396s and btw thank you all for helping me out here since I'm too knowledgeable on this subject :drunk:
 
#16 ·
From what I've been told
See, this is all you have to go on.
When I was a kid, I bought a couple of motors like this, not knowing what was in them an taking the word of the seller. I got burned a few times, so I stopped buying any motor that was advertised as running or "runs, but needs plug wires" for instance. Ever since I have been buying parts only or motors that I can see what is wrong for parts and assembling them myself, I have had no further surprises.
Magnaflux anything that is ferrous for cracks.
Zyglo anything that is not ferrous for cracks.
What you see is what you get.
TRUST NOBODY.
 
#14 ·
That version of the 396 only had approx 9:1 CR.With the current cam & maybe even shorter pistons,it could be less.The "GOOD" 396's & 402's had a lil better than 11:1 & a decent flowing aluminum head.That's not a bad price for a fresh turnkey 396,provided it's a quality rebuild.If you could get it @ a lower price,all the better.A roller cam & a good set of heads would put you in a whole different ballgame.You could. Prolly sell the heads on EBay.That shortblock would be a really good foundation to build on.
 
#15 ·
The most plentiful 396 was the 325 hp. This had oval port heads, 10-1 compression. hyd cam and a Q-jet. The next up was the 350 hp. Only produced for a couple of years. Basic oval port with better hyd cam and a Holley 4 bbl.
The best was the 375 hp. Also rated at 425 in certain instances. Rectangle port heads, 11=1 compression, forged pistons, forged crank, solid lifter cam, aluminum intake (and heads on some) Holley 4bbl.
The least was the 396 2bbl. engine in 69. Low hp gas hog!
 
#17 ·
The stock 69 396 with a 2 bbl carb,"truck engine most likely"was rated for 275 HP.The higher HP rated engines were aluminum headed 11:1 CR engines.Previous 396's were rated for over 400 HP.1969 was the lowest rated 396 produced.Even for the Hi Performance Versions in Chevelles & Camaros.
 
#18 ·
"TRUST NOBODY."

In my many years of buying engines for use and for shop cores. I learned that early on. In my eyes it's a basic $50.00 core engine. Then we work up from there. The prooven work performed adds to the value. Go from there.

All small blocks are 4 bolts from the fastest Corvette in town and were just recently rebuilt and doesnt have MUCH wrong with it. Just need room in garage oe money for something else.. Yada Yada.

I was at an auction last month where several engines were sold.. One, for example, was being sold as a "fresh" 427 L88. Less intake and oil pan. It had oval port heads, dome forged pistons, cast crank, 3/8 rod bolts.
Auctioneer was not happy with me as I called it a fraud.. then explained the only thing remotly L-88 was the forged tall dome pistons..
I did buy, at this same auction, several tall deck 427's and some 396 blocks for $35.00 each..
 
#20 · (Edited)
I shouldn't have stated them as facts.Sry.I should have stated them as what I thought I remembered.LOL.I'm pretty sure on the 275 HP for the lowest 2 bbl version.As far as the Hi Po versions,I was speaking from what I remembered from an article on the Chevelles.Didn't mean to mislead.I should not have stated them as facts.As you stated,there were iron headed versions in between of various HP ratings.The choices for 69 were the slimmest lower versions offered for the 396 tho.
 
#22 ·
ok i looked at the pictures close. i see over spray on the gas line also the heads have no paint where the intake bolts up. also saw over spray on one valve cover gasket tab. also missing a head bolt and bolts are painted . the other side head bolts are black and not painted. also looks like some over spray on the spark plugs. hope the helps.
 
#25 ·
I think I'd pass on this 1.The overspray is no big deal.It coulda came from maybe some touchup after assembly,but,a missing headbolt along with everything else ???? Even tho he has reciepts & you verfied machine work,it doesn't guarantee that he & his Dad did a quality job of assembly.IDK where you are located,but,if very far,your looking @ an additional $500 to $600 in shipping costs.There's really nothing special about this particular model 396 that would make it special even if properly built.
 
#28 ·
Yea that's what's in it I did go over to look at it today and hear it run it is a nice block but it did have touch up work done with engine enamel spray paint the wires are mix match since he did have new ones but they were burned by the exhaust ports
 
#30 ·
the receipts on it were accurate i even went to the machine shop it was done at today. i offered a lowered price $2200 he said he can accept that since he just really needs it gone because hes leaving in less than a month to the army what do you guys think should i do it?
 
#33 ·
@ 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.
 
#34 ·
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".
 
#35 ·
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....
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top