I972Nova

ok....

engine 1 is 433 (.030 over 427) with ls6 rectangle port heads 2.25 valves .712 roller cam, 13:1 pistons, dimple rods, stock crank. dart intake, 1050 dominator carb.

engine 2 is 377 (.030 over 400 block with 350 stroke) Dart 230 runner heads, 2.08 valves, .649 roller cam, 13:1 Ross pistons, eagle h beam rods, 4340 crank, victor Jr intake, Holley hp 750 carb.

I am trying to figure out rough hp numbers for both of these.

I am running a 230" dragster with 4.1 gears. 5400 stall 8" converter. weighs 1775 (sbc) and should be about 1900 with the bbc..

Any ideas on HP and / or what they might run???

I have both of these sittin here, just trying to figure out whether to buy BBC or SBC headers!

thank you in advance...
Josh

hammertime

Id go with BBC .. not sure HP for either just think the big block will work better in the long run.

MileHighMan

Josh. I voted for the big block because it should be very fast with the 4.11s. The cam seems too small for the converter at your weight. JMO. Dan.

fla1976

I voted for the BBC only because I have run a 377 and it was very good. But it seemed to work harder than the cars running big blocks. In the long run, I believe that equates to more maintenance for the SBC.

jmarksdragster

While I am a SB guy, in the long run you will be better with the BBC. The converter should be fine, it is more a function of cam duration than lift, but in reality what RPM range the engine makes power. The 433 should have in the neighborhood of 650 HP and run at least mid 8's in the 1/4. Used BBC dragster headers should be easy to find in good shape, try to stay around 2 1/4 " primaries. The 377 could run close depending on head prep and cam, but will have to turn up the RPM's more and need a little more converter.

edvancedengines

I have not yet voted becuase I see this as an unfair comparison. The SB you offer seems to be a better matched combination that what you are considering for the Bb 433 cu in package. If SB I suggest to get some revvs.

Normally I would have selected the BB 433 but you have tied it down with component choices beginning with the heads. The LS6 Closed Chamber Heads are not the best in the world.

Convertor will be pretty good for the BB.
Convertor change might workl better for the SB.

Your choices of cylinder heads is putting a head on the SB that is far better than your BB choice. The SB could maybe benefit with more cam and some good rpm.

If you are talking the 1971 LS 6 Open Chamber heads the story changes quickly.

Just opinions, not really knowing more about cam or other things.

Suggest to try just using regular headers and swap sides and turn them upside down to find what you want.

Ed

I972Nova

thanks everyone for your input. I am a die hard small block guy, but I got a very good deal on the big block.

These are open chamber heads, they were on a 468 with the same roller cam and went 9.40's at 2800 pounds in a chevelle.

I just was unsure of the smaller big block. If it runs mid 8's I would be very happy for what I have in it...

thank you all,
Josh

zipper06

Don't want to throw gas on the fire, but the 377" in my Malibu, ran 5.16 and 8.23 @ 158 in a 230in hardtail dragster @ Memphis. That was with Brodix track 1 heads angle milled to 52 cc's and 2 1/2" hilborn stacks on alcohol, with 4.56 gears and 5500 stall converter. In the Malibu it dosen't run nearly as good because of the weight and the cam is too tall .668, no torque and 3250lbs., also i'm running different heads and a toilet bowl. The dragster weighs 1750 also.
Bottom line i would go with the big block, for reliability and it's just easier to make run the #'s you're looking to run and i say that with having run nothing but small blks. for the last 20 yrs., but i run them hard.

JMO

Zip.