[jamessh10]

so ive had my engine built for boost, and GPI ported my heads. My passenger side bank is leaking coolant bc of the port.. anybody else have issues with gpi? Its very annoying, the car was out of commission for 3 months due to GPI taking 2 months to send a set of heads, and then not even 1000 miles put on it, its fouling the plugs and misfiring like crazy due to coolant leaking through.. i knew something was up since i picked up the car, my coolant reservoir kept going dry..

[dmcmahan60]

Brett at Pray Performance. Find someone else to work on your car. Sorry for your bad luck. tell us what you decide to do after you get things sorted out. I would hold them liable for the issue also.

[jamessh10]

Originally Posted by dmcmahan60

Brett at Pray Performance. Find someone else to work on your car. Sorry for your bad luck. tell us what you decide to do after you get things sorted out. I would hold them liable for the issue also.

i would get brett to do it, but im not trying to wait 10 months for a set of heads. GPI will deff send me a new one, and due to the fact that it will be free i guess ill stick to there heads.

hopefully everything will be good with this one.

GPI didnt do the work on my car, they just ported the heads. Everything else was done at my local shop and machine shop.

[dmcmahan60]

All good and hope you get it figured out. Good luck and keep us posted. And yes he is a busy man but see nothing but good work from him

[Village Idiot]

Originally Posted by dmcmahan60

Brett at Pray Performance. Find someone else to work on your car. Sorry for your bad luck. tell us what you decide to do after you get things sorted out. I would hold them liable for the issue also.

Good luck ever getting a response from him lol

[Joshinator99]

I felt like aftermarket was the best way to go on a boosted motor as the deck is beefier, not to mention awesome flow numbers. Take your pick: Mast, Edelbrock, CID, etc. The Mast and Edelbrock are US castings, to boot.

[Puddin]

Yep had a set of ported stock heads from TSP do the same thing. It's not the port job causing it though it's the casting from GM. Mine were so bad that it caused my motor to hydro lock and bend my rods from GPI. In the end it kinda worked out for me because I got a hell of a deal on a new 427 short block form TSP and threw some CID heads on it and havent looked back since.

[jamessh10]

Originally Posted by Joshinator99

I felt like aftermarket was the best way to go on a boosted motor as the deck is beefier, not to mention awesome flow numbers. Take your pick: Mast, Edelbrock, CID, etc. The Mast and Edelbrock are US castings, to boot.

i wish i would've went aftermarket heads but unfortunately im about 20k into the build and just want the car running. I do not want to spend any more money on the car right now, and GPI will send me another head for free. i just got it back after 3 months of waiting, it actually took so long bc GPI took 2 months to send the heads to my shop. with that being said i guess im going to just take the free head from GPI...

[3.8TransAM]

While it's not exactly a super common issue it happens enough. Most heads you see anymore are CNC ported, so once the port design is done thats how they all get done. Have a set of heads with enough core shift and it's over with.

[jamessh10]

Originally Posted by 3.8TransAM

While it's not exactly a super common issue it happens enough. Most heads you see anymore are CNC ported, so once the port design is done thats how they all get done. Have a set of heads with enough core shift and it's over with.

well i figured gpi had it figured out, but they are supposedly sending me a new head this week

[Puddin]

Originally Posted by jamessh10

well i figured gpi had it figured out, but they are supposedly sending me a new head this week

It's not something GPi is supposed to figure out. Core shift happens at the molding process of the cylinder head from GM. It's affected several different shops including the likes of TSP and LME. While my car was being done at HHP they had two others with the same issue. It's just the luck of the draw whether you get a bad set or not.

[JasonGofast]

My stock ported passenger head had a crack that leaked coolant into my exhaust as well. Additionally the exhaust valves were bent. Got it replaced for free (not the labor though...) and waiting for a health check now to see if it was all just the heads.

Somewhat regret getting the stock heads ported because now that it's happened to me once I feel like it's a matter of time before it happens again. Only issue I've ever had in my build so far.

[Smokin19]

I wanted to port my heads on my build but, the builder and I decided the extra cost did not give back enough hp to make it worth it. Reading these threads tells me I might have dodged a potential bullet.

[KingLT1]

Originally Posted by Smokin19

I wanted to port my heads on my build but, the builder and I decided the extra cost did not give back enough hp to make it worth it. Reading these threads tells me I might have dodged a potential bullet.

LT4 heads do not seem to have core shift issues like LT1's.