Tell me truth about aftermarket heads

**oldfox** · 08-19-2011, 10:59 PM

I'm looking at used engines short and long blocks and heads.
And I just got to ask,, When your just street romping is there that big of a difference in aftermarket heads? Like how much difference is there between getting a set of trick flows over getting a set of Edelbrock's?
I mean yea I'm looking for better power but to what point?
I'm even looking at a set of the heads from china.
what have you guys had good luck with?

**PaceFever79** · 08-20-2011, 10:00 AM

With a 671 blower, I'm not sure it matters what heads you use.

Even a set of large chamber 351w or GT40 heads will make it stupid fast! lol

**John4cam** · 08-20-2011, 01:37 PM

If you just want to wake the car up you could go with any of the big name brand heads.

Some people just eek every last hp out their setups by carefully planning out and examining the whole setup. Cam, intake, heads/porting as a well thought out combo is where the most power is.

**Silverhatch** · 08-20-2011, 01:50 PM

Originally Posted by John4cam

If you just want to wake the car up you could go with any of the big name brand heads.

Some people just eek every last hp out their setups by carefully planning out and examining the whole setup. Cam, intake, heads/porting as a well thought out combo is where the most power is.

Exactly, for the average enthusiast any name brand would do. Look at some head comparisons in the mags, usually they are within 5-6 hp of one another.

**oldfox** · 08-21-2011, 03:55 AM

I was looking at the gt-40 (iron) also
I can get them ready to go (all fresh)from a shop with a good reputation for $330 a set. Do these flow good compared to aftermarket?

**cam303** · 08-21-2011, 10:33 AM

Originally Posted by oldfox

i was looking at the gt-40 (iron) also
i can get them ready to go (all fresh)from a shop with a good reputation for $330 a set. Do these flow good compared to aftermarket?

nope!!!

**Balaska347** · 08-21-2011, 10:49 AM

I would not buy cheap china make junk... two reasons, one they are JUNK, you get what you pay for. There is more to it then just how well they flow. Two why do people continue to buy china made products, that is whats wrong with this country.

**PaceFever79** · 08-21-2011, 11:48 AM

World Windsor Sr heads are a good budget head.

They flow good and can be had for around $1000 or less used.

They also have 64cc chambers for more boost.

**PaceFever79** · 08-21-2011, 12:01 PM

Something to consider is a stock 5.0 block can't stay together with more than 550 HP
and really 500 HP is more reasonable. With a 6-71 blower, you don't need a big head
to get 500 HP. I bet ported GT40 heads could get you there.

To utilize big heads you'll need a $3500 all forged Dart/Boss short block.

So why waste money on big expensive heads?

**pRojekt02GT** · 08-21-2011, 02:50 PM

Originally Posted by Balaska347

There is more to it then just how well they flow. Two why do people continue to buy china made products, that is whats wrong with this country.

Completely agreed 110 percent

**oldfox** · 08-21-2011, 04:12 PM

I run about 10-12 boost and buzz the stock short block up to 6,000 rpm
and I haven't had any problems. Other than head gaskets

**PaceFever79** · 08-21-2011, 05:27 PM

It's the peak horsepower that will distort or split the block.

The main webbing and cam galley can't handle 500+ HP for very long.

I'd guess 12 psi @ 6000 RPM is probably in the 450 range.

**mgtf289** · 08-21-2011, 07:53 PM

I took off ported CI 289HP heads & bolted on Trick Flows smallest set right out of the box & got 65 HP gain @ the wheels. Its not as important w/ boost, although a quality valve job will help. Find a shop w/ a Serdi machine.

**John4cam** · 08-23-2011, 02:01 PM

Intake side of the head isn't important with boost, but the exhaust side is..

**TooFast98Cobra** · 08-23-2011, 02:25 PM

Originally Posted by PaceFever79

It's the peak horsepower that will distort or split the block.

The main webbing and cam galley can't handle 500+ HP for very long.

I'd guess 12 psi @ 6000 RPM is probably in the 450 range.

stock blocks can handle 525-550 with a good tune no problem.

**PaceFever79** · 08-23-2011, 05:19 PM

Sparingly, yes! But "no problem" is a stretch.

Depends on blueprint work, forged internals. He's running a stock 5.0 shortblock?
I think even 500 HP is pushing your luck with the stock 5.0 parts.

Then again, no shortage of more stock shortblocks! ;)

**TooFast98Cobra** · 08-23-2011, 05:26 PM

gotcha, I meant just the block itself.

**RSbeast** · 08-24-2011, 12:10 AM

A large plus with aftermarket heads is the wall thickness is greater and helps to hold down headgaskets and are less prone to warpage when it does happen

After owning an AFR prepped 5.0 there's not a chance in hell you're getting me to go back to a stock head. My brother's worked GT40s combo seemed alright and made very good dyno #s...but it was about 6-7mph shy of mine on motor vs the AFRs

**Mark Aubele** · 08-24-2011, 11:27 AM

Originally Posted by oldfox

I was looking at the gt-40 (iron) also
I can get them ready to go (all fresh)from a shop with a good reputation for $330 a set. Do these flow good compared to aftermarket?

I had a stock short block with GT40ps, N41, and knockoff Performer RPM intake with a T-Trim Vortech pushing about 14 psi. Car was a monster. No dyno numbers or trap speeds (never made it to the strip, was a hillclimb car, blew that combo up pretty quickly), but for 300 bucks, can't go wrong. Won't have to worry about quality issues like the chinese heads either.

Basically took an NA combo that went 12.50s@109 on street tires on RR suspension (475 lb. coilovers, etc.), and strapped a blower on it.

**yeahloh95** · 08-24-2011, 11:45 AM

with that big blower the alum heads would help offset all that extra weight and it could make more power with less boost , my stock short block is going on 10 years of boost!