1971 SBC 400 Versus 1967 BBC 396 Stock rebuilt , with cam and intake upgrade .

Need do the tests with equal comparisons so to apples to apples. Id like to see how they both would compare to the LS 6.0 LQ9 engine as well.

I pulled the 400 out of my old Blazer 35 years ago and put in a 396 bored .060. The machinist that did the work asked me if I thought the big block really was that more powerful as the 2 engines are so similar in bore and stroke and total displacement. Well, the big block has much longer intake runners that give it more torque, the reason big blocks are so streetable and also the big block has way more air flow, so more horse power. I'm guessing a stock 400 small block has about 175cfm max air flow on the intake and a stock oval port 396 from 67-69 has 260ish? If you're a head porter chime in but I think this is probably close. So the gains in power are to be expected. But a small block 400 with a set of Trick Flow or AFR heads is a very impressive engine indeed!

It's pretty amazing to see these two engines side by side , it really shows the difference , very cool !

Just dropped in an shp 406 in my 57 gasser. Even with smallish heads/carb and intake manifold it still lights up my 12 inch slicks.

I'd take the 400 anyway of the week over a 396 ! Had one in my 46 Chevy coupe stock other than headers, she was Strong ! 👍

Thanks for sharing. I own both. A stock 1975 2 bolt main 400 sb and a 1968 396 bb bored 30 over 750 double pumper almost complete. Looking forward to my tests. Very helpful, thanks again. Truck Driver Ray

We built a blueprint 406 and it has iron eagle heads flowed and ported polish roller cam lifters makes serious power out of a small block in a 66 chevy 2 fun car

Great info. Thank you for putting this video out. I'm sure with the comp cam xr276hr and a good set of aluminum heads, the 400 sbc would pick up a lot. Again, thank you.

Hi, just heard of your channel from Eric W. I really like the content around streetable BBC & SBC motors. I used a 396 (408) 2 bolt main steel Chevy crank eagle 6.8 rods , home ported rectangular port heads with an 8:71 blower in 1996 - 99 , alcohol injected in a rearend dragster for bracket racing. 7:10 at 197 best Now 71 yrs old I have 2- 408 BBC with 781 heads planning on building for my daily driver truck.😊

Stock vortec heads would wake that 400 up.thanks for sharing.

I put vortecs on the last 400 that I had. It ran really good. Summit 1107 cam

Thank you for the video With that SBC ,if compression could be in the mid to upper 9's with a set of lightly cleaned vortec heads , I bet it wakes up a bunch , I have a stroker 383 with a mild cam and it has over 400 Lbft at 2500, 480 @3500 and around 420HP @5200 rpm , using a Quadrajet carb and a Edelbrock performer manifold. and vortec heads.

Both numbers were slightly higher than i expected with such mild internals. Everybody loves Chevrolet and im not a hater i just like to be different. Thats why i love my Oldsmobile 455's. Ive done countless Olds big blocks. Most complete running cores are a dream to work on, never ever find a ridge in the bores no matter the mileage. The only surprises that sometimes come up is spun rod bearings on #7-#8. Other than that most crankshafts will pass for standard size bearings with a simple polish. For years ive designed my own custom camshafts from various cam grinders including, comp lunati and crane. Just doing bowl work and mild porting on stock cast heads, a healthy well thought out camshaft and stock high(er) compression cast pistons (1968-1970) and a single plane holley street dominator intake i can make an honest 510hp at 5900 and 515tq peaking around 4800. All this can often be done without having to visit a machine shop, as long as you check everything and pay attention to details. I have a handful of "tricks" that do help these numbers. The main point im trying to make is that a person can still build a decent 500hp engine with very little overall cost, and i think that would appeal to alot of people out there.

I had a 396 and 400 sitting in my garage.I chose the 400 no question.The 396 would win because of the head flow.I decided to go 400 for weight with aluminum heads and if you build these little dinosaur motors,OMG they are still a threat on the street.Bolted some AFR heads on this 406 sbc and off I went.Putting N/A LS motor behind me.The torque is insane.Great video thanks a bunch.

A set of 441 or 993 with a 1.94 valve and bowl blend and a good valve job that 400 would be around 450 easy...

Enjoyed this. Look forward to the SB Head swap

Both engines appeared to have giant big tube headers on the dyno! Cool vid, would love to see afr 220 heads and a hyd roller in that 400!

I'd like to see another test with these engines (or equivalent) each with AFR heads, maybe 210s or 220s for the sbc 400 and 265s on the 396, similar cam profiles, Performer RPMs on each and same carburetor. That would be fascinating to me.

Keep us posted on the 400 SBC. Recently dropped a fresh rebuild (406) into my Chevelle and I'm fairly satisfied to this point. Always room for upgrades, though. Anxious to see what the new heads will do for yours. Thanks for sharing!

That's a good point!!