I have a 89 formula 350 runs stong only 59000 miles and was wondering if i were to put a set of slp runners on would i notice any power difference and is it worth doing with no supporting mod's except a ait foil and kn thanks

 

probably not unless they are siamesed, and then youd need to have the base and plenum ported to feel a seat of the pants difference. not worth 300 bucks just by themselves.

your best bet is to start with exhaust, headers catback etc.

good luck!

 

http://www.summitracing.com/parts/WND-7540/

Instead of buying the runners..... Think about this piece.... You of course have to buy fuel rails though...

 

It should pick up alittle bit with siamesed runners if they are siamesed atleast 1.5" or so. It will shift the power band upwards alittle and flow just a tad more so more power can be made. Broaden the torque curve for more area under the operating range which usually means a quicker car. You may not feel the difference but the difference at the track will be seen.

These motors do run abit rich up top end, so leaning them out could help when combined with the runners.

 

My 91 GTA has the dealer installed SLP package on a stock L98. It included the intake runners, exhaust headers, exhaust system and ECM prom. Car pulls a little harder than a stock L98, but I don't have any numbers as I don't race this one at the track. Don't have any baseline numbers anyhow, as the car came that way delivered to the original owner.

Good luck!