I was reading super chevy and the are doing a story on gm v-8 performance. In one part, they say that in 1966, gm engineers "stroked" a 396 and had a 427. Is that true scoop? I have a 402 block and was wondering if it can be made into a 427?

Treat magazines as entertainment and nothing more. Both engines have the same stroke at 3.76". The 396 has a 4.094" bore while the 427 has a bore of 4.251".

If you bore the 396 to 4.125" and use a 4" stroker crank you get 427 cu. in.

Mikey,
I saw that too. The author screwed the pooch....should have said enlarged the cylinders not stroked it..... Pitiful proof reading.

It's feasible but just not done. The 396 block was bored .030" by GM to make the 402 and still labeled the engine a 396. Boring any motor over .060" is risky let alone boring a 4.096 block .154" to get 4.250" when one already exists.

As far as stroking a 396 block with say a 454 crank you run into Web clearance issues - not saying it can't be done but not worth the trouble when the larger bore block exists.

As far as stroking a 396 block with say a 454 crank you run into Web clearance issues - not saying it can't be done but not worth the trouble when the larger bore block exists.

KB has pistons to make a 434 bbc with a 4" stroke crank out of a 396.

Speedomotive Makes The 396 To 434 Kit,chk It Out On The Net.

Scott

I bored my 396 (2 bolt 961 block) to 427. Cylinder walls were sonic checked after bore- roughly .100-.150 thick,so I did a 1/2 fill on the block for support. Also added center 3splayed caps to bottom end & the good eagle rods/steel GM crank. This is a 66 chevelle street car with AC/Vortech blower/fuel injection. Water & engine oil run very normal temps.

It can be done-poor people have poor ways.

I don't think there is anything risky about boring a BB .060" over, other than your piston choices get slim for the next rebuild.

You can bore a 396 .155" over if there is no core shift. Which would make it a 427. But when it's done it's a boat anchor, unless you sleeve it.

Tall decks can go .125 over with no issues.

And a 454 crank can go into a 396 if you grind .050" clearance between the bottom of the cylinder barrels and the crank/rods.

I don't know anywhere else that someone can get the kind of info that you guys give out. I really appreciate all the input. Thanks a million(which in today's economy is about 700 thousand!!!)

my 396 is bored .090 over,no problems here, making it 414ci, when ordering pistons you will have to say .060 over 402 other wise the sales rep might say you need special order pistons..........

Just go out and find a 454 block that can be had for 100 bucks. Its standard bore is 4.250 then thow your 396 steel crank in it and a set of 427 pistons and your ready to rip. :thumbsup:
Ask me how I know:D

I had a 427 stroker kit, .030 over 396 with a 4.00 stroke crank (same as a 454) from Speed-O-Motive. It was a kick ass little motor! Torque out the wazoo for a stock 396 block. That was one of the best engined cars I've ever had. Nice sounding idle with 16" of vacuum and it pulled hard to about 5,500 with dual quads. There's no reason why the Tech Center boys couldn't have easily made a stroked 427. I know a guy that worked there in the 50's through the 80's and they did a lot playing around with custom made cranks, rods & pistons for experimental purposes as I've been told by someone who was there.

It's a nice alternative if you want to use a 396 block. I really like the idea of having a stroked 396 that looks other-wise totally stock. A sleeper 396. You can use a 454 block and do minimal grinding for clearance, if any at all.

The 65 & 66 396's are known to have beefier cylinder walls that make the 4 1/4" bore an easy thing to do. 67 and later have to be sonic tested.

Here's a video of the 427 El Camino. I never could get it to hook up in 1st or 2nd ;)
YouTube - 1967 El Camino 427 5 speed