Debating..

[swamp rat]

I want to replace my Doug Thorley Tri Y headers mainly due to having to run stubby plugs all the time, the question is should i stick with headers or go with replacement corvette manifolds.

Which would be better for a 4X4 application? all comments welcome

http://www.1aauto.com/chevy-corvette...FQwEaQod20cAeA

Or

http://www.speedwaymotors.com/Corvet...fold,9133.html

VS these.

http://www.summitracing.com/parts/su...del/k20-pickup

Thanks!

[Stocker]

Opinions are probably gonna be all over the map.... Personally I'd go with the ramhorns. They flow pretty well and should have zero problems or maintenance, ever. Headers, well, some like 'em and some don't, but they seem much more likely to give you problems of one sort or another if you own them long enough. Perhaps more importantly, I question their usefulness on a typical truck engine where there's more emphasis on torque than on high RPM horsepower. I loved the equal-length Hookers that I put on my old '65 Corvette, but it had an engine that was happiest at higher revs.

[Mike C]

I had a too big cam in the Jimmy with headers and swapped the cam to something more 4x friendly. Several years later I ditched the headers and went to the 'vette manifolds. At the same time I increased the exhaust from 2 1/4" to 2 1/2". My butt-o-meter said there was no change in power or economy going to the rams horns, but no header bolts or collector gaskets to deal with along with much easier plug changes made it all worth the while.

So my vote would be rams horns all the way.

[swamp rat]

2 votes Ram Horns no votes headers...

[special-K]

Either is good. Different experiences for different people. I don't see enough reason one way or the other to feel all that strongly about either. I'm a header guy from way back because I always thought they were cool,like a tach,4spd,posi,hood scoop,deep dish wheels... I have had more issues with manifolds than headers. I'd rather replace a collector gasket than a donut gasket. I've had more of those leak than collector gaskets. I learned to double gasket collectors way back and now they make better gaskets. I hate dealing with manifold studs,but who doesn't?
I had a brand new custom built dual exhaust run to manifolds done in my '71 Custom Camper before the big trip to Grand Canyon in '89. On the descent off the North Rim one of the manifolds fatiqued and blew out. I got to a muffler shop in Flagstaff,but we couldn't locate any manifolds. I ran Blackjack AK5000s on my stuff back then,but all he could get in town were El Cheapos (Cyclones?). Just burn-off black paint. My nice new exhaust had to be dog-legged to run to the headers I didn't want. Oh well,now it had headers...that's cool. Well,that whole exhaust system w/headers was the last time the exhaust was touched till I stopped driving it in '04.
In '04 I put headers and a custom made dual exhaust system on my '72 K2500. That's what's on there now and I haven't touched it. Still sounds great. No leaks. I usually run Hedmans because they are made well and not the most expensive. The '72 has Torque Steps (I had coated) which I don't think they make anymore. I have their coated Elites for when I build a new motor. These are full-length.

[duallyjams]

X 3ram horns if done correctly they are maintenance free and they reduce under hood engine noise in the cab. Headers are good if you have a engine thats thumps pretty good.

[swamp rat]

Ok guys, if i buy ram horns do i need the outlets to be angled back or straight down, i haven't had the stock manifolds since about 1995, don't think i have even taken notice of a set since then..

Anybody happen to have a pic of there K20 with a set?

I don't know if the stock set dumped on the middle or the rear, but if i do this i'd like to find a set of corvette manifolds of threy will work with a 350/T-350 combination.

[Ziegelsteinfaust]

I have corvette ram horns on my K20 but haven't done the exhaust yet. I have plenty of room. Pm me and I can text u a pic.

[Stocker]

My stock '72 K20 has center dumps on both sides. I believe 2WD trucks were angled back.

[special-K]

4wds require rams horns (center dumps),same as Corvettes which have 2 1/2" outlets

[fun in dirt]

I went this last go round with the same manifolds you are talking about from Speedway...love em! Every vehicle before I've had headers, but unless it's some super big high HP motors I will do manifolds from now on. So much easier to change spark plugs & no more headache with routing & melting plug wires.
I feel you on the shorty plugs; years ago I had a Chevelle with angled plug heads & that's would fit in them = total PITA!

[argonaut]

I prefer cast iron manifolds. They keep more heat in the exhaust gas rather than in the engine compartment. And unless its a pretty high performance motor those ram horns, especially the larger diameter corvette ones (stock truck ram horns are not 2.5") will flow plenty well.

[swamp rat]

Placed an order for these today. Now i need to get some really good high temp paint to keep them looking nice ( if thats possible LOL)


Thanks for all your help

http://www.speedwaymotors.com/Corvet...air,58966.html

[Mike C]

Eastwood Manifold Dressing.

[special-K]

Get them ceramic coated. If you do your own coating I suggest sandblasting first. That will allow the coating to really "grab". I reused some headers when I rebuilt and engine once. I sandblasted them and painted with VHT. That stuff really stayed on there. Before that,the stuff wouldn't hold up for squat

[ETKTRYD]

I'm with special-K.... Blast and paint. Your just wasting time and money if you dont.
Had a pair of AK-5000s back in 78' They Rocked !!!!!!

[OrrieG]

Ram Horns on 350 in 59 frame with front motor mounts. Used POR-15 hi temp engine paint, brushed on great smoothed up and no dusty residue like the rattle can stuff. After a few engine runs is rock hard and still nice and grey.

[swamp rat]

OK, The corvette ram horns are on back order, i was shopping around for prices on having the exhaust done and one place said that for my engine/truck he would not go past 2.25 diameter on the pipe, i mentioned the corvette manifold and he said he would still neck it down to 2.25. All the other places said they could do 2.5" pipe and not one said it was too big.

My engine build being fairly mild, flat top pistons, .020, maybe .030 over? cant remember to long ago, mild cam, the machine shop that did the work said about 325 hp and a ratio about 9 or 9.5 to 1.

Should i cancel the corvette manifold order and go with stock manafolds and 2.25? or stick with my plans and use the corvette and the 2.5? will i loose too much bottom end?

I have had my Headers and 2.5 for a long time, i cant recall if i felt any any bottom end loss. It defiantly flows nice at freeway speed tho.

[Stocker]

My non-scientific opinion -- big engines, or high performance small engines, need a free-flowing exhaust to unleash the power that's built into them. Normal, run-of-the-mill smaller engines don't need a big, free-flowing exhaust, but neither does it hurt them. I do not buy into the theory that any engine needs a restrictive exhaust. Rather, the engine simply needs to be tuned to work its best with whatever intake and exhaust systems are bolted on. Your truck with headers & 2.5" exhaust have been working well. If a free-flowing exhaust was hurting it at low rpm, you'd know it.

[swamp rat]

Hey guys, does the stock exhaust manifold have a 2" collector or a 2 1/4 collector? thanks!