523 BBC vs 406 SBC

425/409ER

425/409ER

Well Known Member
Here's something I found interesting today after going to the 1/8 for some TnT.
My fallen friends Nova today ran the best with 680hp, 11:1 523 BBC at 6.89@102mph
A couple of years ago my 11:1 406 Vortec SBC ran 6.82@99mph.

Now I know I didn't make that much hp but I honestly thought with that much power his old car would run at least 6.60's, so after today I am very proud of my little 406 that had Stockish heads with mild porting, small hyd. flat tappet cam, $59 headers and stock rocker arms,

The 523 BBC has Bowtie aluminum heads, Dart intake and has some of the best parts money can buy. I need to put that engine back in my car again so I can go head to head with this Nova, it has a few more mph on me but that does not win the race. Long live the SBC FTW!:winner
 
Skip FIx

Skip FIx

Well Known Member
When I had the aluminum rod roller E head 455 in my 78 Trans Am with the loose 5000 stall convertor it would 1/8 6.90s @ 100. Best quarter 10.94 @ 123. Weight 3750 with me and through a 3" exhaust. 1.51 60 fts. Of course that was in good air which is rare here:) Convertor was so loose just pulling up on the trailer ramps it was flashing to 3000! Current pump gas motor not as fat 60ft or 1/8 but a better street convertor.

Nice little 406! Probably a lot lighter than his 532! Heck I was moving parts around the garage the other day and an aluminum BBC Bowtie head is a heavy mother!
 
425/409ER

425/409ER

Well Known Member
Well here's some info I figured out yesterday, the Nova was super lean. The QF 1000 he has on the car sports 75F jet and 82R jet. From Holley their spec say 82F and 88R, so I figure this 523 has 6.60's in it.
 
425/409ER

425/409ER

Well Known Member
Skip FIx said:
Surprised not lean popping!
Click to expand...
On the 2 passes I made in the car, the 2nd one I shifted to high gear early to leg it out and did get the best ET of the day but the big engine would not pull past 6K and acted like a rev limiter. I'd love to get the car rom my friend but he want like 35K for it and I'm not paying that kind of bread for a moore door car. With some tuning and suspension work it's got a 6.50 in it.
 
425/409ER

425/409ER

Well Known Member
UPDATE: I now own this car as of last Sat. One of the 1st. things I did was get rid of the HVH adapter spacer, not that it's bad but on this Dart intake it's bad causing reversion I think. So I put my Eddy open spacer adapter on for the 4150/4500 deal, then I popped on my 1000 Race Demon for a trial run. While it does not idle the best (not setup for this engine) the car ran fantastic down the road, no jerking, vibrations or popping out the exhaust. Took the 1000 QF race-q carb apart to find it's jetted 10 sizes lean on both ends, and I am not sure who tuned this for my buddy but It now has close to stock jetting in it. I suspect that the clown that did this said he could get his 500" BBC have good gas mileage. What a dope. :roll
I'll see how it runs today, and when I scan some of the paperwork he had you guys will get a kick out of that.
 
303Radar

303Radar

Well Known Member
Supporting Member 2
425/409ER said:
UPDATE: I now own this car as of last Sat. One of the 1st. things I did was get rid of the HVH adapter spacer, not that it's bad but on this Dart intake it's bad causing reversion I think. So I put my Eddy open spacer adapter on for the 4150/4500 deal, then I popped on my 1000 Race Demon for a trial run. While it does not idle the best (not setup for this engine) the car ran fantastic down the road, no jerking, vibrations or popping out the exhaust. Took the 1000 QF race-q carb apart to find it's jetted 10 sizes lean on both ends, and I am not sure who tuned this for my buddy but It now has close to stock jetting in it. I suspect that the clown that did this said he could get his 500" BBC have good gas mileage. What a dope. :roll
I'll see how it runs today, and when I scan some of the paperwork he had you guys will get a kick out of that.
Click to expand...
It wasn't jetted for gas mileage, it was jetted for altitude, like 12,000 ft of altitude! :lmao
 
425/409ER

425/409ER

Well Known Member
Skip FIx said:
I know a lot of carb experts say start with the factory settings to go back to baseline. The holley 850 DP(4781) on my 455 that will run 10.90s is just one step leaner based on wide band readings WOT and cruise.
Click to expand...
The old 4781 850's are still one hell of a good carburetor.
 
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