3200 lb S10, runs 6.50s, seems to labor a bit in my opinion and shows some inconsistent 60-330. 750 alky carb and 1000 alky carb seem to be about the same. .640 lift roller, 200cc Brodix heads. Converter flashes about 6100-6150, stays pretty flat for about .75 then climbs to shift at 6900, drops to about 6350-6400.
Anybody made a rear gear change like that? Just curious, sitting here in the off-season with not much to do I guess;-)
I would try and drop the shift point. My 406 has more cam, and better heads and I am shifting at 7000.
I think going to a numerically larger gear would make thinks worse as I think that head is choking the engine. I think you need to drop the shift point or consider better heads if your wanting to turn it that much. Problem with dropping the shift point is your converter is loose.
Imho, your combo seems to be mismatched between the heads, converter amd shift point.
Bill Simpkins 74 Nova SBC 406 3240 pounds Speierracing heads
60 1.27 (10/16) 1/8 6.03@111 (10/16) Best 9.87@131 on the rev limitor 1 Feb 2013
That was on the other end of the "plan" a set of better flowing heads. On that subject, what are some recommendations without going crazy. Would like to stay in the under $2000 range if possible.
Thanks for the input. We have ran 565 and 632 BBC for two decades and the SBC is new to me.
I may be the desenter here. But while I agree the heads may be a hold back, and maybe lowering the shift point wouldn't hurt and might help.....I still think that the gear change could help. A little carb and timing tuning might pop the flash of the converter up just a little as well. Probably be a little out of breath at the big end, but not enough to hurt your mph. Just one opinion. I would guess it to pick up 400 rpm....a little more numerically but real life 400 or so.
Foxtrot Juliet Bravo
Posts: 6463 | Location: Illinois | Registered: July 08, 2004
A friend pulled the plug on a twin to my sbc 427 after having Weigartner port, polish, flow a set of Brodix T1's.
The cool thing about these heads I think, is you can run a set of crane gold rockers, no need for shafts, with standard valve spacing and they flow as well as my out of the box Brodix 233's.
They're for sale, he's got a set of Crane gold rockers too. All brand new never run.
I think he's still got the cam that matches mine, specs wise, for sale as well. I'm surprised he hasn't sold that with the shortages of cam cores, alhough he's not advertising it. I've sold everything so far, word of mouth.
Nice chit.
This message has been edited. Last edited by: Mike Rietow,
Jok, With a better matched head for your engine combination, you’d probably find that not only is the present 4.86 gear OK (which I believe), it could up the launch stall by as much as 200 rpm and this would also make it better imho.
The convertor in my 388 stalls @ 6150 in 4000’ of DA, and 6550 in minus -700’ of DA. On average it’s 6300+. I shift at 6925 and shift completes at 7015. My 7.20 SLR allows it to ride the convertor longer than most.
I believe this next statement, and my convertor stall selection is based on it…….. “You want to be on the ragged edge of driving through the converter and it slipping. What happens by doing that is as the weather cools off, the engine makes more power, and the engine will drive through the converter, thus helping it be consistent versus getting faster”.
Posts: 2692 | Location: 53056 | Registered: December 30, 2009
Been my experience on small blocks the more compression the better. Mine is at 14.8. Any head thats CNCed between 215 and 227 should work great. Mine has 4.71 gears but am a lot lighter than your truck If only 1/8th I would use the 5.00 gear
The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
Posts: 428 | Location: des moines iowa | Registered: January 10, 2020
What happens by doing that is as the weather cools off, the engine makes more power, and the engine will drive through the converter, thus helping it be consistent versus getting faster”.
Every single combination I have been involved with has been more consistent with a converter that was a little too loose in cool dry air. Just as you said. Too loose is generally more consistent.
Foxtrot Juliet Bravo
Posts: 6463 | Location: Illinois | Registered: July 08, 2004