Need help with an engine for my fiero.

[Old Lar]

The 3.1 from the Lumina/Transports are fairly identical to the 2.8. The 3.4 from the Camaro/Firebirds are internally balanced, but the Fiero intake and valve covers bolt right on. I'd work with the 3.4 for you have more displacement to start with and more HP from the start. The 3.4 was rated at 175 HP while the 2.8 was rated at 135 HP. So you should have fewer problems getting to 200 HP with a 3.4. Most any modifications to boost HP greatly will shorten engine life and encourage reliability issues.

[coop8267]

if you want to juice it you better build up the top end. those perf heads and valves should be enough. the engine kit will be good too. go with a roller cam set cuz its way smoother and more reliable. i would think the 2.8 will handle the nos better than the 3.1 would but i dont know for sure

[Ragtop_Renegade]

Originally Posted by goatnipples2002

I also heard that the 2.8 and the 3.1 are identical except the crank. I was told if I replace the 2.8 crank and cam with a 3.1 crank and cam I will have a 3.1?

Well, you do have to bore the cylinders to 3.530" or you'll have a more like 2.9

If you go with a roller cam you WILL need a thrust plate behind the timing gear or you'll have little pieces of Fiero everywear in a rather short period of time.

[goatnipples2002]

I was told not to get roller rockers or rollers arms (or whatever they are) I was told to get a cam with higher lift.


perf. heads
perf. rebuild kit
arp rod bolts
forged rods
272 or 260 cam
75 or 100 shot


That should give me 250-275 whp, I hope.


About the fiero rods some say GM forged them others say they aren't. Wich is it?