[slowbird]

That is definitely a large header. Not sure if you're trying to get the 80tq that your dad is up or what you're looking to gain. But my honest opinion is it'll take a combination of intake and header work. If the plenum is so large you're having issues on the leave that's definitely not right and you will see gains once that is fixed (I'd bet your shift recovery is bad also due to it).
One thing you could do with the headers is move to a 4 or 4.5 inch collect and lengthen it. See how that works. I'm guessing yours are removable so that would be a very easy thing to test.
Fwiw, I ran 2 1/8 to 2 1/4 4" collector on my 1050hp 511ci.

[Matt1970gto]

Originally Posted by slowbird

That is definitely a large header. Not sure if you're trying to get the 80tq that your dad is up or what you're looking to gain. But my honest opinion is it'll take a combination of intake and header work. If the plenum is so large you're having issues on the leave that's definitely not right and you will see gains once that is fixed (I'd bet your shift recovery is bad also due to it).
One thing you could do with the headers is move to a 4 or 4.5 inch collect and lengthen it. See how that works. I'm guessing yours are removable so that would be a very easy thing to test.
Fwiw, I ran 2 1/8 to 2 1/4 4" collector on my 1050hp 511ci.

I just want all I can get & not pull the motor out every 4 or so passes. Apples to apples dads dyno #s were with his two 1050s so I was happy to get as close as I did. His motor made peak trq @ 5800 & mine @ 6700. Peak hp for him was around 7600 & for me over 8000 each piull. As far as shift points once it clears up it’s pulls strong through both shifts. 2.24 lenco 4.56 rear it leaves hard.

[slowbird]

Originally Posted by Matt1970gto

I just want all I can get & not pull the motor out every 4 or so passes. Apples to apples dads dyno #s were with his two 1050s so I was happy to get as close as I did. His motor made peak trq @ 5800 & mine @ 6700. Peak hp for him was around 7600 & for me over 8000 each piull. As far as shift points once it clears up it’s pulls strong through both shifts. 2.24 lenco 4.56 rear it leaves hard.

Interesting, how different are the cams? By the numbers you posted it would seem your cam is quite a bit bigger?

[Matt1970gto]

Originally Posted by johnta1

Launch RPM?

Originally Posted by slowbird

Interesting, how different are the cams? By the numbers you posted it would seem your cam is quite a bit bigger?

Dads is 280/294 .855 .837 115 lobe sep
Mine 284/306 .954 .936 121 lobe sep

[slowbird]

Originally Posted by Matt1970gto

Dads is 280/294 .855 .837 115 lobe sep
Mine 284/306 .954 .936 121 lobe sep

Just curious who picked/made you cam?
I would try another cam.

[Matt1970gto]

Originally Posted by slowbird

Interesting, how different are the cams? By the numbers you posted it would seem your cam is quite a bit bigger?

Originally Posted by slowbird

Just curious who picked/made you cam?
I would try another cam.

Engine builder & LSM.. I had a twin to dads cam in it at first but it was worse.

[PAUL K]

Originally Posted by Matt1970gto

Dads is 280/294 .855 .837 115 lobe sep
Mine 284/306 .954 .936 121 lobe sep

There is going to be a huge difference between those two cams. That second one is going to move the power band much higher in the RPM range.

[Matt1970gto]

Originally Posted by PAUL K

There is going to be a huge difference between those two cams. That second one is going to move the power band much higher in the RPM range.

Yea, dad’s motor only dropped 11hp from 7000-7800 but by 7800 it was dropping. My motor just starts making good #s @
around 7800 & I pulled it to 8400. Only 7 passes on this setup & no clean runs yet but I was only crossing @ 7550-7600 @ Gainesville for the gator nationals this year.

[Stan Weiss]

Originally Posted by Matt1970gto

Yea, dad’s motor only dropped 11hp from 7000-7800 but by 7800 it was dropping. My motor just starts making good #s @
around 7800 & I pulled it to 8400. Only 7 passes on this setup & no clean runs yet but I was only crossing @ 7550-7600 @ Gainesville for the gator nationals this year.

Can you post dyno sheets for both engines?

What does each engine have for stall speed?

Stan

[Matt1970gto]

Originally Posted by slowbird

Interesting, how different are the cams? By the numbers you posted it would seem your cam is quite a bit bigger?

My heads were also hogged out. Once dad’s new set of 5s & his new intake are ready I’ll decide whether I take his old heads or back up & punt. These 5s made good #s on the dyno but we haven’t seen the gains on the track to match the #s. I gained 100hp & lost 60ft lbs of trq compared to my 535 with 11 degree eldebrocks. Dad gained 140hp & about 80 fr lbs trq over his 535 11degree combo. We throttle stop race & the cars are running the same mph with this combo than the old. Both 535s had cams in .763 .780 range & both cars went 5.20s on a single carb i@ Huntsville Dragway.

[johnta1]

Launch RPM?

[Matt1970gto]

Originally Posted by johnta1

Launch RPM?

Originally Posted by slowbird

Interesting, how different are the cams? By the numbers you posted it would seem your cam is quite a bit bigger?

Sorry it didn’t post the 1st time for some reason but 5800.