Had been running a stock GM HEI but it just didn't feel right, as it would start breaking up around 5000-5500 RPM.

Installed a new MSD w/6A ignition box, set my base at 17, centrifical at 21 so it all comes in at 2700 RPM and MAN did that engine come alive !!! :D

From a dead stop with T-400 and kick down selinod dis-connected, convertor unknown,in drive with no power braking, it smoked through first gear, hooked up in second and never missed a beat,up through third !! graemlins/hurray.gif BUUUUTTT

Now once I re-connect the kickdown selinod and try it again it spun up to 7000 RPM :eek: and still wanted more before shifting. I let off the gas for a split second and it shifts into the next gear.


My question is this,
What safe RPM should I expect the shift to occur or does this transmission normally shift at those R's if called upon and what about the motor?

The stock tach redlines at 6000 and only goes up to 7000.


69 Chevelle
396/375 Hp L-78(stock crank, pistons(new rings and rod bearings) and stock sqaure port intake),049 oval port heads,Holley 750 single pump ( thinking about getting the double pump, I know )Harland Sharpe rollers, and hydrlic crane cam 226/236, T-400 w/3.73 12 bolt

Maybe I should post this in transmission section,Sorry.

Either way I can't wipe the grin off my face, since the engine never ran so good or hard since I rebuilt it graemlins/thumbsup.gif


Now I can finally get to the track and get those numbers !!!!!! :cool:

Any advice on the shifting issue would be Great.

Thanks, Love this place !!!!

Maybe I shouldnt have been lazy and sold my MSD box with my stang because I was too lazy to transfer it to the malibu. redface.gif

I have come across HEIs that had weak coils. They ran but not really right. It's nice to change something and have it wake up your car that much.

400 bucks for summit WELL spent in my opinion !!!!


Just took the wife out for a ride to prove it was worth it.

Pulled out of the driveway and she said "well it sounds better"

Got out on the cause way across the meadows from the island to the mainland, pulled over until it was clear, and.....................................

Showed her what 400 bucks got us !!!!

She was squirming in the seat and had white knuckles buried in the dash..

Slowed back down and she said that's great...now take me home, :confused:

GEEZ, At least I was excited !!! HeHe.

Anyway anybody got any thoughts on the shifting issue?

Thanks,
Wait a minute the wife's calling, said to bring her some clean panties, no wonder she wanted to come home !!!! LOL

Did you change distributor too?

Ahem. Word of advice. Take wifey out to nice dinner and tell her you really appreciate the support she shows for your hobby. It will pay dividends down the road, mark my word.

Rapid Robert


Yes I did change it, can't think of the model # of the top of my head. It has the external coil. Went with the MSD Distributor, MSD SS blaster coil, and MSD 6A ingnition box.

Breathed all kinds of life into my set up :D

I am glad you fixed your ignition problem.

Just want to make sure that no one thinks that if they have a Properly operating ignition system that installing an MSD or Crane or Accel or Jacobs setup will make their car faster... because it won't.

AC,

Just saw the thread - you and I have a very similiar set up - same displacement, cam and rear. Only diff is '290 ovals (2.19/1.72's) and an Edel Perf 2-0. Currently running a Summit HEI with an upgraded coil. My motor does not break up but feels like it hits a wall and power flattens out at 5000.

This is ironic - it has been suggested that the limiting factor may be the intake. My CR is 9.5/1, your's is probably the same with the original 11.0 pistons and the open chambers.

Did you HEI ever run correctly and also did you ever run your set up with an Oval Intake?

mc71454

Very true,
But if it's NOT properly working it may be worth investigating.


GRN69CHV

My HEI ran GREAT.............under 5000 RPM, above that it ran like CRAP !!!!

I used the blue springs with the MSD and got it all in around 2700. Would like to get some track numbers and maybe experiment from there.

Honestly though I don't race the car and most likley will leave it be..........but ya never know.


The mis-match oval port heads mated to the square port intake was because I wanted to keep the stock L78 intake was given the 049's and had them rebuilt with 2.19 and 1.88's

PLUS racer 1320 ran this set up and swears that it pulls AWESOME from mid range on up.

With this new ignition I see what he means !! graemlins/hurray.gif

Sounds good. :D

ACLineman, I had a friend that used to run oval port heads on an otherwise stock, '66, 375-396 and it flew, mismatched intake and all. High 12 second range @ 112 MPH with 4.10 gears,four speed and open exhaust. Didn't bite too well but the tires weren't too good in 1967.

Sounds good Harold,

I can't wait to get to the track !!! graemlins/thumbsup.gif

Anybody got any suggetions about my original shifting question in the first post?