So many told me that I'd lose power if I put on the SLP runners and ported plenum on my 305. Man where they wrong! I had them put on yesterday along with a new tune-up and sensors......what difference! The car pulls so much harder past the 70mph mark. I ran her all the way to about 5200 rpm and it was still pulling! I ran out of road so I shut her down. This is on a peanut cammed car. I noticed the difference in throttle response, all around power! Felt better than when I added my headers!

 

Do you have a stock base manifold?

Nice butt dyno results

 

Who told you that? I musta missed the post. I'm a big fan of SLP runners. My experience was that they didn't help much until I matched the openings on the side of the plenum with the odd "figure-8" shaped openings of 2 of the runner pairs. Port matching the plenum to the upper runner opening, basically. If you haven't done that yet you're in for another pleasant surpise when you do!

I used SLP runners to the low 13s on a nearly stock bolt-on 350 TPI car years back. That was my expereince with them.

 

excellent work boys, you just answered my question, ill be buying them now. think about how could more airflow make you lose power. thats like saying hondas where ment for high gas milage and economy. oh wait they where. 98pds of torque hoo ray where fast now.

good job on the runners

 

I'm not knocking your mod, cause I actually think they did help. But a good tune-up can do wonders for the butt dyno. Now go get a bigger cam and some higher flowing heads to go along with your new found breathing capabilties

 

I hear what you are saying about the tune up. I have kept my car in pretty good condition with regular maintenance so I give the tune up it's due credit. I gotta give the m,ajority of the credit to the runners and port matched plenum because I know what the tune up has done in the past. One thing is true about a minor loss in low end torque. Nothing upsetting but it did help prevent me going sideways off the line.
What mod would you guys recommend next: 3.42's, UD Pullies, ED Wright Chip, lca's&panhard, or swap the flowmaster for hooker catback.

 

Can't really tell ya' which mods made the difference as they all went on at the same time, but I have the following and it made a world of difference on my 305tpi!:

- SLP Runners
- Portmatched plenum
- CompCam
- Roller Rockers
- Edelbrock TES headers
- Edelbrock RPM cat-back
- World Products S/R Torquer heads
+ little things like airfoil, K&N's, afpr etc.


Ken