Im stumped and could use some outside perspective

[Bent77]

Engine hp is estimated at 220 hp, what's the possibility I'm just not pushing enough hp for the 3.73's?

My last 86 w/ 305 had upgrades and was closer to 300hp.

I don’t know, had stock trucks pull to 120 at high altitude

 

[SilveryFox]

Doing the math, at 70 I should only be turning 2200 rpm. So I'm not out of gear. And definitely shouldn't be at full throttle to keep 2200 rpm.....

 

[Bent77]

If the transmission was set up incorrectly internally, I suspect that you would have some evidence of damage or burned fluid

You mentioned your fuel pressure at the start. Do you have a way to check that it maintains pressure at speed?

 

[SilveryFox]

Bent, not reliably, only abto verify pressure maintains throughout the rpm range (with no load)

 

[Wes Harden]

I can say that mine, will do 75 at 1/2 to 3/4 throttle on flatish highway. Any grade 3% or more I begin to slow while adding more throttle. Set up is different 4.88's with 33's and I am closer to 2700rpm, the beginning of my torque curve. I don't recall mine trying to down shift into 3rd till below 60, and will up shift @ 63, normally I shift down to 3rd and run to 65, until the hill is done.
I am running a q jet, Edelbrock 1902 which has a published cfm of 750, I think your 600 is to small

 

[SilveryFox]

The 600 is normally good to about 400 hp(crank hp) after that I agree on the 750, Wes.

It just is odd to me about this whole thing. My Silverado weighs more, has 300hp stock on a 4l80 with 4.10s and will cruise all dang day at 95 without downshifting. Granted it's injected, but still.

 

[SilveryFox]

I pulled 5° (roughly) of timing out of her tonight and I can almost sustain 70 on a flat now. Aftermarket cover with no timing tab on it. No clue on actual timing

I'm thinking the timing is off on the cam/crank gear. Maybe a tooth off?

 

[Wes Harden]

Could be most chain set can't be trusted to be 0° most are retarded. Esp from the factory in late 70's up

edit: I plan on advancing mine 2-4°

 

[JoshHefnerX]

Sounds like you need to figure out a timing tab, so you can verify.

 

[Polymath]

I thought my old 305 had no timing tab, then I noticed it was hidden behind the water pump. You have to look straight down from the top center of the motor to see it. Maybe that's the case with yours too.

 

[Wes Harden]

yes 85/86 up timing tabs were at 12 o'clock.

 

[SilveryFox]

This one is absolutely tab free. Some stupid chrome ebay thing. Everyday I find something new that's messed up

 

[shady]

My old burb with factory 350tbi had 3.73's and 33" tires.
Anything above 55-60 would disconnect the lockup and hunt 3-4.

 

[Blue85]

stock timing, accel Dizzy

This one is absolutely tab free.

Giving us misleading information doesn't help anybody.

 

[Bent77]

yes 85/86 up timing tabs were at 12 o'clock.

My 77 has that, I am assuming yours did too. When did that period start?

 

[Polymath]

I think you need to get a proper timing cover on there. Or use this as an excuse for an LS swap or something.

 

[CyberSniper]

What does it do if you disable the vacuum advance?

 

[Wes Harden]

My 77 has that, I am assuming yours did too. When did that period start?

 

[SilveryFox]

Giving us misleading information doesn't help anybody.

Yooper, what I meant was stock timing setup, no jesel drive

 

[SilveryFox]

Update: got a timing cover to match the damper marking.
Timing was only "off" 4° at idle -->12° BTDC on the light, new distributor was defective. Put old distributor in, same timing, same everything. 90 is difficult to hold unless it's dead flat, but 75-80 is doable now without full throttle.