ported and polished heads on an idi?

Macrobb

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I've got to find pictures of my own... With ZF5 and 4.10s(and turbo), they tend to top out around 92 ish; I've seen over 100 with a double-overdrive system.... Not that I was driving that fast myself, mind.

The turbo is the big difference - N/A you'll barely get into the 80s, especially with a worn out fuel system/motor. The great thing about a turbo is that it really doesn't care how worn your motor is; just add more boost and it'll make power!
 

Thewespaul

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I've got to find pictures of my own... With ZF5 and 4.10s(and turbo), they tend to top out around 92 ish; I've seen over 100 with a double-overdrive system.... Not that I was driving that fast myself, mind.

The turbo is the big difference - N/A you'll barely get into the 80s, especially with a worn out fuel system/motor. The great thing about a turbo is that it really doesn't care how worn your motor is; just add more boost and it'll make power!
I think this run we calculated a bit over 125 mph
 

icanfixall

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I have posted many pics of my porting and traveling in double overdrive showing the mph and the rpm. I recall 1850 was 75 mph. I think 2000 rpm was speedometer pointing straight down... So I "had something left"... My rear gears are 3;55. So in double overdrive my final gear ratio is 1.96 per the Gear Vendors calculation sheet. At those speeds on California's I5 driving home from a west coast gtg is where I recorded this...No engine winding out sound either. Just the slight sound of wind passing the cab. My interior has 2 layers of Fat Mat sound insulation so its very quite... My trans is the Brians Truck Shop E4OD backed up by the Gear Vendors. Just those two items are over $8400.00... Not boasting... Just showing the cost of going fast...The trans has the extra deep Mag HItex pan that holds and extra 2 gallons of trans fluid. Only God knows how much of a mess thats going to make when I change it out.Probably getting a small plastic kiddy pool to catch all the oil. Nothing else has the capacity to hold that much fluid...So I have been told.. Once the plug comes out there will be no stopping the flow....
 

Ford420ci6point9

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I have posted many pics of my porting and traveling in double overdrive showing the mph and the rpm. I recall 1850 was 75 mph. I think 2000 rpm was speedometer pointing straight down... So I "had something left"... My rear gears are 3;55. So in double overdrive my final gear ratio is 1.96 per the Gear Vendors calculation sheet. At those speeds on California's I5 driving home from a west coast gtg is where I recorded this...No engine winding out sound either. Just the slight sound of wind passing the cab. My interior has 2 layers of Fat Mat sound insulation so its very quite... My trans is the Brians Truck Shop E4OD backed up by the Gear Vendors. Just those two items are over $8400.00... Not boasting... Just showing the cost of going fast...The trans has the extra deep Mag HItex pan that holds and extra 2 gallons of trans fluid. Only God knows how much of a mess thats going to make when I change it out.Probably getting a small plastic kiddy pool to catch all the oil. Nothing else has the capacity to hold that much fluid...So I have been told.. Once the plug comes out there will be no stopping the flow....
That is my dream to get an idi running like a new truck and quiet with a zf5, maybe turbo idk I like N/A it's unique and sounds great. I wanna get some fat mat for mine right now cause I have just straight pipe and it roars in the cab also because my c6 wont stay in 3rd below 40 mph no matter what. is there a knows problem with the c6's not staying in top gear? I know it has enough torque to pull the truck up a small hill in high. It just won't even if i tap the throttle below 40.
 

IDIBRONCO

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is there a knows problem with the c6's not staying in top gear?
Not that I've heard of. Maybe the VRV needs to be adjusted or replaced.
I wanna get some fat mat for mine right now cause I have just straight pipe and it roars in the cab
A turbo would make the straight pipe quite a bit quieter. It also reduces intake noise.
 

Garbage_Mechan

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I have cleaned up the radius under the valve seats and done a little blending on the the ports nothing big. The 90 7.3 with Banks Turbo and a little added fuel ran better than the 96 7.3 PSD I replaced it with (needed a crew cab) I was pretty happy with it.
 

Garbage_Mechan

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Of course once I “tuned” the 7.3 PSD there was no longer a question but the 7.3 IDI with a little port work was a strong runner.
It isn’t a lot of work to blend the bowls, clean up the radius a bit and streamline the valve guide bosses. There is no possible negative effect as long as you don’t start trying to make things bigger just more efficient. And it pays you back,even if just a little, every mile (and smile)
 

Garbage_Mechan

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As to the question on the C6 coming out of 3rd too easy....
Make sure you have plenty of vacuum.....should be at least 18 inches IIRC....there are test specs on the pump.
Be sure the kickdown linkage is way out of adj or stuck in the kickdown position.
If not try connecting a vacuum line directly to the trans modulator with nothing else. Bypass the VRV. It should shift very early and hold gears very late before downshifting. If not there is a modulator or trans issue.
 
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