which head is better "G" or 782

[turbovan89]

I picked up a G casting head some time back because I heard that it can really wake up a 2.5 tI. My van will be down for a tranny rebuild so I thought that this would be a good time for a head swap. Now I have read that the "G" is not necessarily the way to go. Here is what I have:

T3/T4 .63 trim
Stock tI intake
choice of stock or 3.8 minivan TB (56mm?)
tII IC
FWD-P stage 5 cal
3 bar map
+40s
AFPR
TurboXS MBC


OK which head do you think I should go with. What are the adv/disadv of each head. Also I have no idea which cams are on either head. I'm not sure how to tell, but I will have a look tomorrow on the "G" head. Thanks in advance.

Deric

[boost geek]

Do you have the intake for the 3.8? If you do, cut off the elbow as long as you possibly can and weld it up to your 2.2 intake. One of the best mods you can do in my opinion.
I dont have enough info to give an opinion for which head to use for a 2.5 and heavy vehicle.

[turbovan89]

Do you have the intake for the 3.8? If you do, cut off the elbow as long as you possibly can and weld it up to your 2.2 intake. One of the best mods you can do in my opinion.
I dont have enough info to give an opinion for which head to use for a 2.5 and heavy vehicle.

Really. I don't have the intake but could probably get one easily. I have a spare tI intake I could try this with. Besides my wife loves any excuse she can to use her new welder. Thanks for the tip. Also just noticed same question in thread titled "head games". I'll follow that on as well for the answers I'm looking for.

Deric

[turbovanman²]

Personally, a good ported 782 head is better. Cutting off the elbow is proven not to really do anything. 58mm is useless unless you get rid of the other restrictions, and you better have alot of money. I saw your thread on the other site and see you are using a Stage 5, I believe thats setup for a 782 head. Run that on a G-head and it will be dog. Also, stage 5 requires high octane gas all the time, otherwise boom.

[turbovan89]

Personally, a good ported 782 head is better. Cutting off the elbow is proven not to really do anything. 58mm is useless unless you get rid of the other restrictions, and you better have alot of money. I saw your thread on the other site and see you are using a Stage 5, I believe thats setup for a 782 head. Run that on a G-head and it will be dog. Also, stage 5 requires high octane gas all the time, otherwise boom.

OK, apparently I need to keep the 782 head as it works best w/stage-5 cal. I do plan of going to a powerstroke IC, and I will port or have the 782 ported while doing tranny rebuild. What should I do for intake? what other restrictions do I need to take care of? I forgot to mention that I have, I think, 2.5" SV and (for sure) 2.5" exhaust (no cat, bullet muffler). Also I have a spare carbed 2.2/523 I was thinking about building an all motor . Will the G be a good canidate for this or should I just sell and use the money for something useful?

Thanks,

Deric

[Whorse]

I think that the swirl heads are very easy to mess up by porting. I was looking into it myself and since I've never done it I figured it's not worth it. Easy to ruin the swirl characteristics.

[boost geek]

If your running a large intercooler, your intake will be a restriction, unless you wanna spend $100-150 on a 2 piece . I'm glad I modded my 1 piece, running a larger t.b. on a stock 1 piece is a waste of time. You can see the size difference on the pic.
If you have a tig welder, I say go for it.

[turbovanman²]

OK, apparently I need to keep the 782 head as it works best w/stage-5 cal. I do plan of going to a powerstroke IC, and I will port or have the 782 ported while doing tranny rebuild. What should I do for intake? what other restrictions do I need to take care of? I forgot to mention that I have, I think, 2.5" SV and (for sure) 2.5" exhaust (no cat, bullet muffler). Also I have a spare carbed 2.2/523 I was thinking about building an all motor . Will the G be a good canidate for this or should I just sell and use the money for something useful?

Thanks,

Deric

Steve aka Direct Connection tested both the one piece and 2 piece intakes on a stock head and there virtually identical, except the one piece has a higher torque peak so I believe its better for ligher cars, the 2 piece shifts it lower so its better for a van. I picked up serious vacuum with a ported head, 2 piece and log header. I think all bets are off with a big ported head and the 2 piece shines. BTW, I have one for sale,
I would port the stock ex manifold, get the 3 inch sv and dp and your off to the races.

[John B]

I'm glad I modded my 1 piece, running a larger t.b. on a stock 1 piece is a waste of time. You can see the size difference on the pic.
If you have a tig welder, I say go for it.

How does the two-piece neck compare to the one piece?

[glhs875]

From what I've seen a 782 head starts to hit a brick wall in the mid 20 psi range due to detonation issues. Huey in his Omni, was dentonating in this range on pure race gas. I have had problems as well, and I know of others that have had the same problem. And if tuned right, a G head can have TONS of bottom end torque. That's just my opinion. For an 8V, I won't run anything but a G!

[glhs875]

How does the two-piece neck compare to the one piece?

It's alot larger in diameter. The runners are 2 to 3 inches longer on a 2 piece. I feel like the runners coild be a little shorter on the 2 piece. I measured them to be 12" including the upper.

[turbovan89]

From what I've seen a 782 head starts to hit a brick wall in the mid 20 psi range due to detonation issues. Huey in his Omni, was dentonating in this range on pure race gas. I have had problems as well, and I know of others that have had the same problem. And if tuned right, a G head can have TONS of bottom end torque. That's just my opinion. For an 8V, I won't run anything but a G!

A discenting opinion,I love it. I do plan on running a lot of boost 20-25psi at times. I noticed in your sig your 1/8th mile times do you go to huntsville dragway, I've been there a couple of times (used to live there). What cal are you using? That might be the main reason everyone else is telling me 782, because of my FWD-P stage 5 cal. I will be in Gurley over the 4th will you be around?

Thanks,

Deric

[John B]

It's alot larger in diameter. The runners are 2 to 3 inches longer on a 2 piece. I feel like the runners coild be a little shorter on the 2 piece. I measured them to be 12" including the upper.

I was surprised that the two piece wasn't really any better than the one piece in the flow testing. I wonder if opening the two piece to 52 mm would make a big difference?

[John B]

From what I've seen a 782 head starts to hit a brick wall in the mid 20 psi range due to detonation issues. Huey in his Omni, was dentonating in this range on pure race gas. I have had problems as well, and I know of others that have had the same problem. And if tuned right, a G head can have TONS of bottom end torque. That's just my opinion. For an 8V, I won't run anything but a G!

I'm pretty sure Steve Menegon was running a swirl on Sledgehammer when he broke into the 11s. He does some chamber work on the 782s that reduces detonation.

[turbovanman²]

John, remember the testing was done with a stock throttle body and stock head. Get a ported one and all bets are off.

As for Swirl vs G head, talk to SMP, he used both and went faster on a 782 head, when he was running the 8 valve setup.

The elbow is a moot point, lots of people have made it larger and had zero gains.

[John B]

What made the comparisons problematic is that the one-piece was opened up for a 52mm while the two-piece was 46mm.

[glhs875]

A discenting opinion,I love it. I do plan on running a lot of boost 20-25psi at times. I noticed in your sig your 1/8th mile times do you go to huntsville dragway, I've been there a couple of times (used to live there). What cal are you using? That might be the main reason everyone else is telling me 782, because of my FWD-P stage 5 cal. I will be in Gurley over the 4th will you be around?

Thanks,

Deric

Iam using a bone stock 86 T1 5 speed cal. Look me up! ( phone# 256-587-6093) ask for Brian. Gurley is only about 15 min away. Yes, I go to Huntsville Dragway some, although the run on my sig was ran at Sand MTN. Dragway. I plan on going to Huntsville soon, everyone usually runs 2 to 3 tenths better at Huntsville between the two. I have dialed in more boost, I may have to put in a 4th stage of boost for 3rd gear, to keep the tires from breaking loose in 2nd gear, and I plan on crushing my best ever pure street time of 8.59 @ 82mph which was run at Huntsville.

[glhs875]

I'm pretty sure Steve Menegon was running a swirl on Sledgehammer when he broke into the 11s. He does some chamber work on the 782s that reduces detonation.

Yea, I've seen his work. No more fast burn on those heads. Might as well be a G!!

[glhs875]

John, remember the testing was done with a stock throttle body and stock head. Get a ported one and all bets are off.

As for Swirl vs G head, talk to SMP, he used both and went faster on a 782 head, when he was running the 8 valve setup.

The elbow is a moot point, lots of people have made it larger and had zero gains.

That may be so, but did both heads flow identical etc, etc. And from what I've gathered, you hit that brick wall I was talking about, and in the mid 20psi range like I said.

[glhs875]

After a good porting job on either head they are basically the same except for the combustion chamber. Do away with the fast burn characteristics of the swirl like alot of people do, and there even closer yet.