$1665 406 Goes 10.65@126mph Wow!

425/409ER

425/409ER

Well Known Member
Put my old 406 back into duty this week and too it out to the track. I was meeting around with it and through the crappy Slowmaster mufflers which turned out to be not so crappy the car ran 10.79@123mph closed exhaust with my ugly old Holley 750. I switched that out to my trusty 1000 BG mighty demon and the car ran 10.70@124 and change. My last pass was after I let that car cool all the way down and cooler track the car hit 10.65@126.05mph I am stocked about this old 406 that has a $300 set of Dart heads and a $25 solid roller cam, LOL. going to run it one more time next week before I try my BBC of for some new head tests. Who says the SBC's are all washed up:laughing
 
1964SuperStocker

1964SuperStocker

Well Known Member
Supporting Member 3
I'd love to see what my little 355ci engine would do at the track. I had it built for my 64 conv back in 1998 and its been setting in the car ever since. Still around 200psi per cylinder with world products heads. The car has the wrong gear for the engine/stall. My guess is I stuff a 4.11 or 4.56 in it and the thing would be dangerous on the street. Power glide/high stall doesn't help but it will get loose on you at 70mph when you shift into second. I told the guy I didn't want to do smokey burnouts, just wanted to do high speed passes on the interstate. It will get up to 120 and just cruise (with the fun floating car feeling). :scared He told me he put a circle track cam in it. NO idea what that means or what any specs it has. Either way, the 355ci would be fun in the right car. Need to pull it and put the 327/300hp back in my conv.
 
425/409ER

425/409ER

Well Known Member
Well I broke the rear end last week with this little monster, was still enough to smoke an AFR headed BBC Chevelle but it's going to get some 4.88's and a little better shocks on the front end. Bought some Calvert 90-10's to keep the front end hiked up so the car can plant the tires better for the next outing. The deeper gearing should help this engine out a bit as the effective ratio was 3.80 and will now be 4.50 with the 30" tires.
 
425/409ER

425/409ER

Well Known Member
Well the day did not go as planned:thumbdown. The best run with the 4.88's was a 10.78@122.6 and now it seems like this combo is just blowing through the converter. Although I finally found a nasty misfire after a few runs the car just would not cleanly pull on the big end. Swapped out the brand new AC plugs:furious for the 2 year old ones and the car pulled cleanly to over 7K, but the ET and MPH just was not there. The first run was my best 1/8 mile as it ran a 1.46 60ft, 6.59@103mph but the big end on that pass was where the trouble started. One lessoned learned was, DO NOT BUY CHINA MADE AC DELCO PLUGS ANYMORE, guess I will need to make a change in converters to see if this pans out so no BBC L29 head test this year as I am sure I could blow that engine up at 7K and I don't think there is any power up there with it anyway.
 
D

Don Jacks

Well Seasoned Member
Supporting Member 3
You may have too much gear for the combo.That's not the first time that I've seen that happen but you never know if a change is faster on not unless you try.
 
425/409ER

425/409ER

Well Known Member
Don Jacks said:
You may have too much gear for the combo. That's not the first time that I've seen that happen but you never know if a change is faster on not unless you try.
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Did not have much of a choice as I had the 4.88's sitting around and this coming weekend is it for me, but you might be right on that too much gearing. I am going to put my pump gas 358 SBC in the car with a tighter 10" converter as I am not sure the 8" will even work with that one and I do not want to spin that to the moon. The 358 ran 11.29 last time out so we'll see how it like something different. Car will have a 9" next year with good parts.
 
425/409ER

425/409ER

Well Known Member
So here's an update from last weekend with the 358. The car with a tighter converter, less engine and same 4.88's ran the best of 11.30@117mph. Most of the gains after a off the trailer 11.64 was from the new FST carburetor I bought and finally got to try and it worked good. It is an 850 vs with all the bells and whistles and for me getting the car to run like this was pretty amazing. I did find out that night it was a little on the rich side so maybe dropping the jetting might have put'er in the 11.20's, oh well I sure had a good time. I even won a trophy:D
 
425/409ER

425/409ER

Well Known Member
Here is something I am thinking of doing for late next year when I get the car out. I will go to a ported 170cc Vortec head with larger valves and some porting, add my S/V off the other 406 and run some smaller 1 5/8" headers. This should bump the torque up and along with refreshed 8" converter I am betting goes in the high 10's.
 
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