Vmax Spacer vs marine intake

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Schurkey

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I went through an ignition module every 6 months which was super annoying.
Verify your ignition coil.

A partially-shorted ignition coil is the usual cause of repeat module failures.

Use an ohmmeter to test primary resistance, secondary resistance, and primary-to-ground, secondary-to-ground.

THEN use a spark-tester calibrated for HEI to assure the coil has proper output voltage.

Ohm-tests alone are not enough. The spark-test is essential.
 

JeremyNH

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This was my solution to the MI EGR problem. I got mine three or so years ago off ebay. If you're lookin for a MI remember that you're looking for a boat part so searching "marine intake vortec 5.7L" or such may not turn up many if any hits. You are looking for a Mercury/Mercruiser Magnum 305 or 350 intake year 2000+. Mine came off of a 2005 Mercruiser 305. Boat yards take them off boats to sell to other boat owners not necessarily truck guys so keep in mind while you're searching. But with regards to the performance question it's an improvement but won't make a difference for towing. Eliminating the flow restrictions is only beneficial at high rpm which isn't really an applicable tow scenario. But it's easy to tune, you can get Bosch EV14 (popular on Ford trucks) injectors to fit it, and you won't have the spider issues to worry about. So no question a better intake than stock. But for performance it's a lot of money for virtually no gain.

In my opinion plenum spacers are snake oil. You'll spend a lot of money, have the future headache of other than stock dimensioning on the motor top, and not gain a thing for the effort. But that's just my opinion having seen them but never tried myself.
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kylenautique

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Verify your ignition coil.

A partially-shorted ignition coil is the usual cause of repeat module failures.

Use an ohmmeter to test primary resistance, secondary resistance, and primary-to-ground, secondary-to-ground.

THEN use a spark-tester calibrated for HEI to assure the coil has proper output voltage.

Ohm-tests alone are not enough. The spark-test is essential.
Before I sold it, I ended up drilling a hole in the distributor body and added a ground wire to it. I know... weird, but it seemed to help. It was a strange problem, and I know ignition modules are more prone to failure on TBI style engines. I used all AC Delco parts too... Needless to say, I always kept a spare and I got really good at changing them in the parking lot ;)

I was going to externally mount the module and try that. Keep the heat off it. But, I sold the truck so I never got to try that solution. Car seats don't fit super great in 1972 chevy k10 trucks especially if I had a passenger.
 

kylenautique

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This was my solution to the MI EGR problem. I got mine three or so years ago off ebay. If you're lookin for a MI remember that you're looking for a boat part so searching "marine intake vortec 5.7L" or such may not turn up many if any hits. You are looking for a Mercury/Mercruiser Magnum 305 or 350 intake year 2000+. Mine came off of a 2005 Mercruiser 305. Boat yards take them off boats to sell to other boat owners not necessarily truck guys so keep in mind while you're searching. But with regards to the performance question it's an improvement but won't make a difference for towing. Eliminating the flow restrictions is only beneficial at high rpm which isn't really an applicable tow scenario. But it's easy to tune, you can get Bosch EV14 (popular on Ford trucks) injectors to fit it, and you won't have the spider issues to worry about. So no question a better intake than stock. But for performance it's a lot of money for virtually no gain.

In my opinion plenum spacers are snake oil. You'll spend a lot of money, have the future headache of other than stock dimensioning on the motor top, and not gain a thing for the effort. But that's just my opinion having seen them but never tried myself.
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So there was not that huge of a difference performance-wise from stock to the Marine intake? That's what I was concerned about. This is the other reason I think it would be fun to return to TPI. The two intakes are very different. TPI has its crazy long runners making globs of low end torque. The stock intake is designed for the purpose to tow and haul, but the runners are not as long, and we still have the whole Spider inside the plenum thing... I think it will be a fun comparison. And honestly, its not that difficult to swap out. I need to make new fuel line adapters and set up the EVAP system, but overall that's about all the big hurdles. The TPI system is pretty plug and play as long as the new owner didn't do anything weird to it. It has an adjustable fuel pressure regulator that is good up to 70 psi, so we are good in that department. My EGR system is already deleted, so I don't need to worry about that. Best part, if I don't like it, I can easily install the stock system and upload my tune.
 

L31MaxExpress

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So there was not that huge of a difference performance-wise from stock to the Marine intake? That's what I was concerned about. This is the other reason I think it would be fun to return to TPI. The two intakes are very different. TPI has its crazy long runners making globs of low end torque. The stock intake is designed for the purpose to tow and haul, but the runners are not as long, and we still have the whole Spider inside the plenum thing... I think it will be a fun comparison. And honestly, its not that difficult to swap out. I need to make new fuel line adapters and set up the EVAP system, but overall that's about all the big hurdles. The TPI system is pretty plug and play as long as the new owner didn't do anything weird to it. It has an adjustable fuel pressure regulator that is good up to 70 psi, so we are good in that department. My EGR system is already deleted, so I don't need to worry about that. Best part, if I don't like it, I can easily install the stock system and upload my tune.
TPI makes midrange torque, not low end torque. I had one, was great around 3,000 rpm, anywhere else better to have a different intake.
 

L31MaxExpress

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This was my solution to the MI EGR problem. I got mine three or so years ago off ebay. If you're lookin for a MI remember that you're looking for a boat part so searching "marine intake vortec 5.7L" or such may not turn up many if any hits. You are looking for a Mercury/Mercruiser Magnum 305 or 350 intake year 2000+. Mine came off of a 2005 Mercruiser 305. Boat yards take them off boats to sell to other boat owners not necessarily truck guys so keep in mind while you're searching. But with regards to the performance question it's an improvement but won't make a difference for towing. Eliminating the flow restrictions is only beneficial at high rpm which isn't really an applicable tow scenario. But it's easy to tune, you can get Bosch EV14 (popular on Ford trucks) injectors to fit it, and you won't have the spider issues to worry about. So no question a better intake than stock. But for performance it's a lot of money for virtually no gain.

In my opinion plenum spacers are snake oil. You'll spend a lot of money, have the future headache of other than stock dimensioning on the motor top, and not gain a thing for the effort. But that's just my opinion having seen them but never tried myself.
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That EGR location would straight up be trying to occupy the same space as my accelerator pedal.

I noticed power everywhere with the marine intake but biggest gains were upstairs.
 

kylenautique

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TPI makes midrange torque, not low end torque. I had one, was great around 3,000 rpm, anywhere else better to have a different intake.
Its going to be fun to compare the 2. My 72 was pretty wild. Tons of power in the lower RPM range. It towed and hauled stuff pretty good, and unloaded it got almost 15mpg (yes the 4l60e had a lot to do with that) Not bad for a lifted truck with the aero dynamics of a brick.
 
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