: LO5 engine upgrades?

425 Dual Quad
10-22-08, 04:55 PM
Hi all!
Well I might be in for a head gasket job on the '93 FWB. (See my won't start post) So whilst I'm at it is there any power and/ or economy mods anyone would suggest to the old beast. It ran really well, pulled well but wasn't as quick as the LT1 but much smoother and quieter.

It's a 160,000 mile motor so nothing too radical. It mainly does the local school run but occasionally gets taken out for a long run to clear it out. I was thinking of a different ignition module and things like that.

thanks all, Nick

10-22-08, 08:00 PM
If I had to do head gaskets on an L05, I wouldn't be putting those heads back on. I would go with Vortec heads. Much better flowing. Comparable to the LT1s. Slip in an LT1 cam (or bigger) while you are at it.

10-22-08, 09:05 PM
From what others have said, you'll need a new intake with vortec heads.

10-22-08, 09:15 PM
Yup, you'd need an intake that matches the Vortec heads. However, the weak point of the L05 is the heads and broomstick cam. A simple head and cam swap and you've just added a minimum 75 ft. lbs. and 50 horses. But that route is expensive. The most cost effective way to bump power on the L05 would be a different cam and headers. You could do the whole thing for $300 on ebay.


425 Dual Quad
10-22-08, 09:22 PM
Hi Guys,
Thanks! - being in Ireland I think new heads would be a touch difficult to do. Although I did once bring back a set of Buick 425 Nailhead heads as personal baggage from New York - they weighed 68lbs each packed - just under the 70lbs maximum weight. Guess you couldn't do it now.

I think it might be over budget also! Now a cam is an idea. What one? I would have thought changing the ignition module for a more agressive one would be the first mod (worked a treat on my L98 Corvette TPI engine) but you've more experience here.

10-22-08, 10:37 PM
You want power AND economy? Just go all out power. I did the Melling M-1 cam, its pretty nice and has smooth idle. ditch the EGR and Smog stuff. One combo I did is the edelbrock spreadbore performer intake with the TBI adapter from transdapt, very good fuel/air mix for those great take offs. I know what headers dont fit, the longtube ones I have(and you can find them on MPLS craigs right now). I would try shorties. Redo all the ground wires including the one in the back of the motor(I used 4 gauge monster wire). If you stay with the original heads, you could do a basic rebuild and that should help. Take those exhaust valves out and scrape that crap off.

10-23-08, 04:31 PM
Check out CFM Technologies


Read through the site, lots of good info on TBi performance gains...