Gen 3 Race Heads upgrade to Gen 4 Heads

[TT VIPER]

I have a 2005 Gen 3 TT Viper with built engine, built heads, 72 mm ball bearing turbos, G-Force built T56, etc. running on AEM Infinity 10. I would like to take this car to the next level. I want to change the car to e-throttle so I bought a Gen 4 intake manifold as I think the design is superior to Gen 3 intake.

I’m also interested in buying a pair of Gen 4 heads. My existing Gen 3 Race heads are race ported, with polished chambers, bigger intake and exhaust valves, Inconel valves and all the goodies. What I would like to know is if I can transfer all the parts in my Gen 3 heads to Gen 4 heads? I would also need to get the Gen 4 heads race ported.

Is it better just to sell the Gen 3 Race Heads and buy entirely new Gen 4 Race Heads with all valve terrain? Is it possible to purchase blank Gen 4 heads?

Thanks for all input.

[LATAMUD]

I have a 2005 Gen 3 TT Viper with built engine, built heads, 72 mm ball bearing turbos, G-Force built T56, etc. running on AEM Infinity 10. I would like to take this car to the next level. I want to change the car to e-throttle so I bought a Gen 4 intake manifold as I think the design is superior to Gen 3 intake.

I

The rest of your message is missing. Sometimes apostrophes cut off and mess things up.

[TT VIPER]

The rest of your message is missing. Sometimes apostrophes cut off and mess things up.

Corrected. Thank you.

[pokeyl]

I have a full Gen 4 (Greg Good ported) top end. Heads, intake, roller rockers, valve cover. 2.14 intake valves... PM me if your interested!

[TT VIPER]

I have a full Gen 4 (Greg Good ported) top end. Heads, intake, roller rockers, valve cover. 2.14 intake valves... PM me if your interested!

PM Sent.

[RedTanRT/10]

TT Viper, you definitely should not go to drive by wire. Produces terrible throttle lag

[TT VIPER]

TT Viper, you definitely should not go to drive by wire. Produces terrible throttle lag

I don't see why drive by wire would create any throttle lag where a stand alone AEM Infinity ECU will be running the e-throttles. I'm planning to run Porsche throttle bodies with some fabrication work to make them fit the Gen 4 intake manifold. AEM Infinity does not care what e-throttle you put there. I need the drive by wire for the traction control.

[J TNT]

I have new stock Gen 4 heads in the box never used. PM me your cell number if you’re interested.

[TT VIPER]

I have new stock Gen 4 heads in the box never used. PM me your cell number if you’re interested.

I'm interested. PM sent.

[LATAMUD]

If you have shaft mount rocker arms, the heads are machined to accept them. The Gen4 heads take a different rocker arm.
The AEM infinity can tune the drive by wire lag out. You'll be fine. My 2008 has no lag with a Arrow ECM. My 03 is getting a TT build on Greg Good Gen5 top end, solid cam, on a Gen4 engine, with an AEM Infinity. I'm going to use the drive by wire setup. You'll need an adapter to get the pedal to mount to your firewall. I'm taking a Challenger pedal, cutting/blending the 03 Viper pedal in to keep the same geometry. Cheaper than the 08+ Viper pedal.
Sell your Gen3 top end, put the money towards built Gen4/5 heads. You will also need new headers, or at least cut the header flanges off and weld on Gen4 flanges to mate up to the heads.

Added: The bolt holes for the Gen4 need to be drilled out to allow for the Gen3 Bolts/Studs to fit.

[TT VIPER]

If you have shaft mount rocket arms, the heads are machined to accept them. The Gen4 heads take a different rocker arm.
The AEM infinity can tune the drive by wire lag out. You'll be fine. My 2008 has no lag with a Arrow ECM. My 03 is getting a TT build on Greg Good Gen5 topend, solid cam, on a Gen4 engine, with an AEM Infinity. I'm going to use the drive by wire setup. You'll need an adapter to get the pedal to mount to your firewall. I'm taking a Challenger pedal, cutting/blending the 03 Viper pedal in to keep the same geometry. Cheaper than the 08+ Viper pedal.
Sell your Gen3 top end, put the money towards built Gen4/5 heads. You will also need new headers, or at least cut the header flanges off and weld on Gen4 flanges to mate up to the heads.

I guess it makes more sense to sell my Race Gen 3 heads with all valvetrain, T&D 1.7 roller rockers, chromoly pushrods and buy Ported Gen 4 heads with rockers and pushrods. I can also make some crazy fabrication to make the Gen 4 Intake work with Gen 3 heads. We'll see about that.

Making the headers work is not that hard. Just change the flange and you're done.

Yeah, the 08-10 gas pedal price is a joke. Any modern Dodge with drive by wire will work I guess or I can get Tilton pedal set if I can locate one.

It does make sense to build a Gen 4 bottom end as the oil pan is upgraded. I have the comp coupe oil pan with swing arm. If you are going to go all in with CNC porting the heads, I don't think Gen 4 or Gen 5 makes any difference. And yeah over 2 bar boost the plastic intake manifold cracks.

[LATAMUD]

I can also make some crazy fabrication to make the Gen 4 Intake work with Gen 3 heads.

If you are going to go all in with CNC porting the heads, I don't think Gen 4 or Gen 5 makes any difference.

If you have a Gen4 intake and place it on top of the Gen3 heads (while they are on the block) the runners don't line up, like not even close. Also the mounting angle is different, not worth trying to mangle an adapter or destroying an intake manifold over.

Agree, Gen 4 or 5 heads, if you are stripping them down and building them up it doesn't really matter what you start with, the end result will be the same. The Gen5 heads have a countersink to allow the Gen5 intake torque limiters to sit flush.

[TT VIPER]

If you have a Gen4 intake and place it on top of the Gen3 heads (while they are on the block) the runners don't line up, like not even close. Also the mounting angle is different, not worth trying to mangle an adapter or destroying an intake manifold over.

Agree, Gen 4 or 5 heads, if you are stripping them down and building them up it doesn't really matter what you start with, the end result will be the same. The Gen5 heads have a countersink to allow the Gen5 intake torque limiters to sit flush.

I'm thinking of doing one of the following:
1. Do some crazy fabbing with the bottom piece of the Gen 4 intake manifold and make it fit to Gen 3 heads but I'm afraid it will flow less than a Gen 4 head + Gen 4 intake manifold setup.
2. Sell my race ported Gen 3 heads with all upgraded valvetrain and buy complete race ported Gen 4 heads with upgraded valvetrain. It will hopefully be a bolt-on this way. This way I can also try to slightly increase my compression and rev the engine up to 7000 rpm instead of the current 6700.
3. Fab my own intake manifold to fit Gen 3 heads but have similar design to Gen 4 intake manifold. Any aftermarket intake manifolds for Gen 3 heads?

[PaulP]

Give Todd a call at A&C performance he did gen 5 heads on my gen3 and cnc'ed them they came with valve train as well,

[TT VIPER]

Give Todd a call at A&C performance he did gen 5 heads on my gen3 and cnc'ed them they came with valve train as well,

I don't exactly understand why you would use Gen 5 heads instead of Gen 4 if you are going to CNC port it and change all the valvetrain anyway with high performance ones. I will give him a call.

Thanks.

[PaulP]

I don't exactly understand why you would use Gen 5 heads instead of Gen 4 if you are going to CNC port it and change all the valvetrain anyway with high performance ones. I will give him a call.

Thanks.

The 4-5 heads are the same besides the limiter pockets, Give todd a call he has them on the shelf ready to go he can explain in depth. Sell what you have and upgrade why waste your time making a adapter.

[TT VIPER]

The more I look into it, it makes more sense to sell my race ported heads with all upgraded valvetrain etc. They have 1000 miles on them. Is there a market for used race ported Gen 3 cylinder heads?

Another option is I can try and fab my own custom intake manifold similar to Gen 4 design.

[Dan Cragin]

For a Turbo Build I would suggest a set of aftermarket castings. JM Stryker Heads are still available and much less prone to head lifting for your application. They cool much better and can be made to flow as good as prepped
Gen 4-5 heads.

The Plastic Gen 5 intake is not the best for forced induction, a ported Gen 4 Aluminum manifold would be preferable. You could run mechanical or DBW Throttle bodies. Gen 4-5 intakes dont have injector bosses (as they are in the head),
so you would need to modify the intake for injector rails.

[TT VIPER]

For a Turbo Build I would suggest a set of aftermarket castings. JM Stryker Heads are still available and much less prone to head lifting for your application. They cool much better and can be made to flow as good as prepped
Gen 4-5 heads.

The Plastic Gen 5 intake is not the best for forced induction, a ported Gen 4 Aluminum manifold would be preferable. You could run mechanical or DBW Throttle bodies. Gen 4-5 intakes dont have injector bosses (as they are in the head),
so you would need to modify the intake for injector rails.

I thought they stopped producing JM Striker Heads. Are they still in production? Who is selling them? If I remember correctly, the JM Striker heads were a direct fit to Gen 3 Intake manifold.

I already bought Gen 4 Intake and I know the problems with plastic intakes under boost. I saw that my fuel rail does not fit the Gen 4 intake. The injectors sit at an angle in Gen 3 fuel rail. I was thinking of buying a Gen 4 fuel rail and make it work with Gen 3 heads or fab my own fuel rail.

[Dan Cragin]

The JM heads are now available again, with some additional improvements. They typically come with rocker arms, but your current setup may change over. PM me if interested
and I could spec those out for you.

[TT VIPER]

The JM heads are now available again, with some additional improvements. They typically come with rocker arms, but your current setup may change over. PM me if interested
and I could spec those out for you.

PM sent.

[ky13]

@TT VIPER, out of curiousity, what is your asking price for your current Gen 3 heads (if you decide to sell)?

[TT VIPER]

@TT VIPER, out of curiousity, what is your asking price for your current Gen 3 heads (if you decide to sell)?

PM sent.

[TT VIPER]

I posted a For Sale thread at Viper Parts and Accessories. Is that the correct place to post for sale?

[Exhlr8n]

I don't see anything listed yet in the classifieds here.