Thinking about Heads

BALZY_GT · Nov 2, 2011

My 94GT has a stock bottom end with a mild cam, edelbrock performer intake manifold, vortech v2 @10psi, anderson power pipe, 255lph fuel pump, 42lb injectors, & msd ignition. Right now i'm making 325rwhp, but looking to upgrade. I want to keep the bottom end stock for now, but I definitely want to upgrade the heads. I was wondering if putting GT40 heads from a 95 cobra would be worth my time, or if i should just pony up the $1,500 for a good set of edelbrock, trick flow, or AFR's? I will also be installing a methanol injection kit at the time of the heads. What do you guys think?

itsblue95 · Nov 3, 2011

with a good set of heads, meth kit, and a good tune youd be in the mid to upper 400whp range id say. id go AFR's but im bias

russ8825 · Nov 3, 2011

If you have the money go for the AFRs.

BALZY_GT · Nov 3, 2011

how much power do you think I could make with gt40 heads? also which roller rockers should I go with?

Garbone · Nov 3, 2011

BALZY_GT said:
My 94GT has a stock bottom end with a mild cam, edelbrock performer intake manifold, vortech v2 @10psi, anderson power pipe, 255lph fuel pump, 42lb injectors, & msd ignition. Right now i'm making 325rwhp, but looking to upgrade. I want to keep the bottom end stock for now, but I definitely want to upgrade the heads. I was wondering if putting GT40 heads from a 95 cobra would be worth my time, or if i should just pony up the $1,500 for a good set of edelbrock, trick flow, or AFR's? I will also be installing a methanol injection kit at the time of the heads. What do you guys think?

Trick Flow "Twisted Wedge" heads for my son's '68 Coug set me back <$1200, complete with guide plates, valves, springs, etc. 2.02" Intake, and 1.6" exhaust, with 61cc chambers, and a flow rate of 185cfm...not bad. They were about the best buy, dollar wise.

94GTstanger · Nov 3, 2011

If it was mine I would get AFR hands down the best head you can get. Do the research...they are badass and outflow others like them. You will get your best numbers with them...

Venomized · Nov 3, 2011

Going with GT40s unless theyre fuly ported to the max is a temporary solution to a long term problem. You need to figure out what you need for flow rate and buy accordingly. I to wanted to do the GT40 route til I figured out they wouldnt flow for the numbers Im looking to put down.

castine917 · Nov 3, 2011

I suggest putting the money you plan to spend on the meth kit towards getting the better heads. GT40 heads are better than stock but, still a restriction to that vortech v2. Power will increase more with afr, trick flow, holley etc. and your 10 pounds of boost will change to a lower # due to the lowered restriction of the better heads and intake temps will lower also. Both the lower boost and temps with the more power means you won't need the meth as much but, adding it later with the better heads will net a greater gain.

rz5.0 · Nov 3, 2011

I would say afr185 if your willing to notch your pistons. If not TFS suggested above.

alex302 · Nov 3, 2011

i have a similar set up stock bottom end, trick flow twisted heads, 1.6 rollers, 7psi with a 70mm turbo and trick flow street heat intake and i made 408hp to the wheels. i have seen other sn with meth and a real good tune making 600+. i would go with the afr, trick flow, victor jrs they are well worth the money.

spdtrip · Nov 3, 2011

I would go with the better heads also. if you shop the classifieds on this site and others, you might find a good deal. maybe someone is doing a stroker and
needs to go larger. Give it some time and keep looking.

BALZY_GT · Nov 4, 2011

do you need to notch your pistons to make afr 185's work?

Musturd · Nov 4, 2011

Yes as stated above you will need to notch them.

BALZY_GT · Nov 4, 2011

does that apply for all but trick flow? whats the purpose behind notching the pistons?

det_riot · Nov 4, 2011

BALZY_GT said:
does that apply for all but trick flow? whats the purpose behind notching the pistons?

notching pistons give your valves room to open. on a stock pistoned car with afr 185s, the way the valves are positioned, when they open, they come in contact w/ the piston. By notching the piston out, it gives the valve adequate room to open without interference from the piston. the reason why trickflows do not do this even though they're the same size valves is because of the angle the valve travels in their design.

itsblue95 · Nov 4, 2011

i didnt notch my pistons for my AFR 185s some say im stupid since i didnt but i have had a problem. make sure you get the right cam to match your set up. with my HCI swap i made 310/316 with messed up injectors. so with the right heads on your set up youd make some good power

rz5.0 · Nov 4, 2011

I didnt notch the first time. But I had to pull the heads for a diffrent reason. When I did I saw were the valves were bearly making contact with the piston. Does not take much and you might find your self rebuilding your heads. Not worth the money. Notching is ez took me 4 hours to do it and have it back together.

94GTstanger · Nov 4, 2011

You do not need to notch piston forget the way heads....they are a bolt on and go item. Only reason you need to notch them is if your cam has to much lift. Speak with AFR when youbuy them and ask what the biggest cam you can safely use with ur stock pistons.

rz5.0 · Nov 4, 2011

I would at least measure. I BET you dont have enough clearance. Even with a stock cam. Just because it wount hit the piston does not mean you have the right amount of clearance. Its not lift you have to worry about its duration how long the valve is going to stay open.

OnyxCobra · Nov 4, 2011

Nobody is going to tell you what cam you can run, you need to check piston to valve clearance. Chances are if you're running any sort of lift you'd need to notch the pistons. If you like AFR the 165s are a 100% bolt on head and despite the smaller valves they still outflow the TFS Twisted Wedge heads. I've had nothing but a good experience with my 165s.