Head Swap Options For 5.7L 350 TBI Engine

PlayingWithTBI said:

They say it'll give you around a 30 LB/FT in torque gain.


That offer was only if you buy their cam, heads, and intake. Then, they'll throw in a chip.

Have you looked into an EBL?
www.dynamicefi.com/EBL_Flash.php

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Majoraslayer said:

EDIT: Actually, it was a post you made in 2020 that inspired me to consider adding a ZIF socket and using 27SF512 EEPROM flash chips instead.

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Majoraslayer said:

This is going to be controversial, but I'm looking into possibly upgrading to an Edelbrock 3704 Performer TBI intake and retaining the TBI heads with it.

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98 Nitro said:

Well the other GM heads that are an easy swap are the TPI ones, but stock wise it is not much of an upgrade, but they have more potential.

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Majoraslayer said:

I want to revisit this comment. I found a good deal on a used TPI long block, so my plans have changed to pick up that block, put together my build on that, and swap the engines. The actual TPI intake on the replacement engine is shot, so I would be sticking with my original TBI plan rather than digging into a full TPI swap. The engine was pulled from a 1993 Camaro. From what I understand, this should also open up new possibilities for a roller cam if my '95 block was one of the casts that only worked with flat tappet.

This should be a fairly simple question from what I've been reading, but are there any fitment issues I'll need to address in swapping TBI headers/intake/accessories onto TPI heads? One comment I found mentioned that GM themselves supposedly recommended the TPI heads as direct improved replacements for TBI heads, so I would take from that it should be a fairly straightfoward swap.

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NMNorsse said:

Sounds like a good plan but maybe a new post.

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Majoraslayer said:

I picked up the TPI engine today, and I'll provide some numbers I found on it in case it helps figuring out what my options may be with building it up on my TBI system. I don't really know what I'm looking for to see what types of cams the block will support, but I did notice it has some kind of metal cover running along the inside of the valley.

Head Numbers: 10128374
Driver Side Cast Numbers: GM 5.7LG SGI E143
Forward Of Passenger Cylinder Head: V0521SAS
Stamped Driver Side, Near Transmission Mount: 1P2124330

EDIT: I read up on decoding these a bit and this is what I determined:

Build Date: 05/21/1993
Cast Date: 05/14/1993
Plant: Flint, Michigan
HP Rating: 275
Options: F, Manual, Oil Cooler

I don't have any experience with TPI at all, so I noticed a few things are different on this that I'm not sure how to adapt. One concerning difference I noticed is that these heads appear to have much different ports from the TBI heads. Primarily, they don't have any ports across the middle where I understand EGR is supposed to go, and it looks like the coolant passages are either missing or have pinholes instead of big square holes. Additionally, I noticed that the water pump had a completely different design, and there's an extra shaft that runs from the valley under the intake out through the timing cover. Are these heads able to adapt directly to a TBI intake's cooling system with the ports like this? I would assume this would involve an EGR delete, but I'm curious how the cooling system will work. I've included a pic comparison of the ports.

While I'm asking questions about TPI......what the heck did they cut off the back of this intake with a hacksaw, per the attached pic? I don't know what's supposed to be there, but I'm sure these nasty saw cuts sure ain't it.

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