3.4 Head And Intake Swap

[grandsport3.4]

i have a 93 firebird with a 3.4 and heard about swapping to 3400 or 3500 heads and intake and wasnt realy sure what i would need from the doner moter for this to work with my 3.4 i heard i could get some more hp by running either of the setups i am hopeing its a bolt up deal

[IsaacHayes]

Fitting under the 93 cowl might be a bit of an issue. The previous gen had more room.

It's not really bolt up. I mean it bolts up but you gotta make other stuff work like accessory brackets etc.

[ForcedFirebird]

At least with '93 you have OBD1!

With some fabrication skills, you can get the heads on there fairly easily. The stock brackets need some holes slotted or re-drilled, but they work. 3500 UIM won't fit, but the 3400 UIM bolts to the 3500 LIM, so you are good there. You need a three wire coolant sensor in the block, or tap the 3500 heads to accept the 3.4 sensor. You need a throttle cable from a 1995 GM truck, they are available from GM for $15. fuel rail from a 3400 will work. I may be forgetting a coupleof details, but this should get you started.

Oh yeah - 3500 heads/gaskets and 3.4 pistons = 11.5:1 compression if you don't want to change pistons.

[grandsport3.4]

ok cool but what throttle body do i use i heard the 3500 is fly by wire can i us emy 3.4 also wich injectors to use thanks for the help

[grandsport3.4]

sorry thought of another q do the 3500 heads have roller rockers factory and if so wich pushrods do i need to use 3.4 3400 3500

[grandsport3.4]

another q my pacesetter headers wont fit either will they

[ForcedFirebird]

I can't remember if the pacesetter headers have large enough primaries to fit the Gen3 heads - if they do, just slot the bolt holes to work with the Gen3 pattern.

Pushrods are a debate when it comes to the 3.4 hybrids. Russel has been using stock Gen2 pushrods for years, but until I bolt a set on my motor an measure - we don't know if they are exactly the correct length (if they are short, max lift isan't being achieved). If you go to full rollers, you will have some adjustability though.

[IsaacHayes]

3500 plenum won't fit but 3400 will and bolts up to the 3500 lower. So you would run a 3400 TB (56mm) on there.

Yes 3500 are roller fulcrum. Pushrods no idea you'd need to measure and maybe get custom. pushrods.net I think is the place.

[rcf4]

What about the 3.4 cam? I'm thinking of doing the same thing. Saw a complete 3500 for cheap. My 3.4 is out of the car and the cam change would be easy. Could I use the 3500 cam?

[ForcedFirebird]

What about the 3.4 cam? I'm thinking of doing the same thing. Saw a complete 3500 for cheap. My 3.4 is out of the car and the cam change would be easy. Could I use the 3500 cam?

No. the 3500 cam is a roller, and the 3.4 is flat tappet.

[923.4v6]

How much differ. in power do you think there would be between the stock 3.4 f/t and the stock 3400 roller?

[grandsport3.4]

thanks for all the help guys

[G-U-NOT]

Oh yeah - 3500 heads/gaskets and 3.4 pistons = 11.5:1 compression if you don't want to change pistons.

Are you serious??
I was thinking about doing a 3500 topend swap on my 3400, but Im going to be running boost soon also, so I dont know about having that much compression.....
What should I do?

[IsaacHayes]

3.4 = fbody iron head RWD engine. 3400= FWD engine. 3400 with 3500 heads will be less compression than a stock 3400 which is 9.6:1 or so. No worries.

[ForcedFirebird]

3.4 = fbody iron head RWD engine. 3400= FWD engine. 3400 with 3500 heads will be less compression than a stock 3400 which is 9.6:1 or so. No worries.

IIRC 9.1:1 3500 heads, 3500 gaskets and 3400 pistons. I'll be changing to 3400 pistons when I put boost back on