i got some SLP runners in the fall of 2003. i herd i was to gain 20 FLYWHEEL hps on a 350. with a 30% drive-train lose that equals 14 RWHP i didn't feel 14 extra RWHPs in my 305. all i felt was a small throtle response increase. anyone else with this problem of no HP increase.

a 20 FLYWHEEL HP gain on a (240 FLYWHEEL HP)350 = 0.08 FLYWHEEL HP gain

a (190 FLYWHEEL HP)305 with 0.08 FLYWHEEL HP gain = 15 FLYWHEEL HP. with a 30% drive-train lose = 10.5 RWHP (COULD YOU FEEL AN EXTRA 10.5 HP GAIN???) i think i should have felt it.

You never get the advertised gains from just one mod.
If you had other mod like heads, cam, intake, headers, ect. the stock runners would be the bottleneck so to speak. the tpi setup was designed for the 305 originally. the runner diameter was specific to the 305 to make the most power. It worked so well they brought back the 350 and put it on that. The biggest gains from the runners are on a 350 motor. you will see a decent gain if you do some other mods to your motor. My advice, replace the 305 with a 350. ( or bigger )

No, you won't feel a 10HP gain in SOTP driving, you'd need a dyno to measure before and after mods for something that small.

Like it was said above, all these advertised gains are usually based on testing on a modified motor. Where, like with your runners, the extra air can be taken advantage of.

they look sweet though

i am planning to get a stroked 350 HO to a 383 this summer. just need a littel more cash

Off the topic, but why on earth stroke a 350HO, when you can purchase the GMPP 383 for the same? It would be warrantied too!

i have a budy with a 350 HO (10,000 miles on it) in a totaled 80s suberben (motor is fine). plus it's only $400.00 .

Ah I see now.

A Vortec headed 383 HO eh? Sounds pretty cool!

I'll take those runners off your hands for $50
Most people should be able to feel 10 hp.

I gained 0 horsepower from mine. I have SLP runners and a ported plenum on and I actually gained maybe .1 in the quarter mile.

if you call slp they will tell you will see a gain with a 350 or a manual 305 auto 305 does not need the air flow these runners produce unless of course you add a cam,better heads etc.the runners are still a good investment and yes they look good especially polished

i suspected the gains were from a non-stock 350.

I spent like two weeks polishing my SLP runners and yes they do look good polished. I have them and an Accel(Superram) base on with them and really noticed a big improvement. I also ported the runners which needs to be done on these. BTW-this whole setup will be up for grabs as soon as I get around to putting my new intake system on.

How did you polish them so fast? I am on about 14 hours on the runners and there is still casting left on them

5 min. polishing mine (acctually father inlaw). but, mine were done on a industrial polisher. wipes the casting right off its a very big machine.

SLp's deff look good..

Dear ***!!! Are you using toothpaste to try to polish them or something?!?!?!?! Pick up some power tools man! For the stock runners, pick up a roll of emory cloth in varying grits from 80 to 200 or so, then put a buffing wheel on a 4" grinder, then a small buffing wheel on a die grinder or a Dremmell type hobby grinder. I think the last set I did took less than 3 hours total, including degreasing!!!

I am doing everything by hand

See ya next year. Check out Eastwood, they have a complete line of buffing wheels and compounds.

Do you have blisters to prove it? 4.5" grinders on Ebay for $5, Eastwood, Harbor Freight, flea markets for buffer wheels, sanding wheels, cotton wheels, and grinders... all have the stuff needed to do it for well under $30-$50...

as far as looks go i like the stockers better than the SLP's. when i get another set i'll go with something that retains the factory look.

im prolly a bit late but doin searches tends to bring back old posts. How much u want man? thats a NICE setup and exactly what i want. is the plenum ported too?

I don't think anyone makes stock looking large diameter runners do they? The Edelbrock's look a little closer to stock, and much sharper looking than the SLP's. However, they are a major pain in the rear to get sealed!!!!!!!

if you put them in as they come of course you wont see a gain, they are stock runner size! thats why there so beefy, so you can port them to hell and back, i opened the divider up on mine cinsiderably, and ported them in further. they let me pull all the way to redline w/ ease.


I saw a.2-.3 gain with them, stock runners are definaty a bottle neck.

Yeah I need polishing tips...

the edelbrocks look fugly i think. AS&M large tube runners look pretty similar to the stockers. i think TPIS and Accel make some too. but the SLP's are the cheapest.