[yellow1098]

Any have a solution for why on my new 461 with new 340cfm e-heads the header position would have dropped so much? I also have new motor mounts on the frames and everything else but not on the engine itself. But these are almost to low to drive with! They are the same exact headers and I had aluminum 87 e heads on before with the old setup. They are DHE-D581 round port hookers

Also is there a different brand of header or anything I can do to fix the problem??

Thank you as always!

[68WarDog]

What chassis is this? And do you have lowering coil springs or other suspension lowering devices? I run 2" Super Comp on my 70 GTO, and have at least 4" of clearance with the 3.5" collectors.

[yellow1098]

I have the same exact suspension I had with the other engine and it’s at least 2 inches lower……could the new lower engine mounts have changed it or maybe the heads are different size?

[tom s]

Bad set of headers.Tom

[NeighborsComplaint]

Originally Posted by yellow1098

Any have a solution for why on my new 461 with new 340cfm e-heads the header position would have dropped so much? I also have new motor mounts on the frames and everything else but not on the engine itself. But these are almost to low to drive with! They are the same exact headers and I had aluminum 87 e heads on before with the old setup. They are DHE-D581 round port hookers

Also is there a different brand of header or anything I can do to fix the problem??

Thank you as always!

I think you answered your own question. The only variable is your motor height.

Headers from the same maker are typically identical as they are machine bent and jigged prior to welding. If a difference occurs, it is fractionaI and the result of sloppy assembly. I recently replaced my headers with the same part number as I was happy with the originals' fit. The replacements fit exactly and when bolted up, even my tailpipe alignment in the valance panels was unchanged.

[25stevem]

Is your ride height the same as before?

A aftermarket iron block will add 40 lbs to the nose of the car.

[67Fbird]

I wouldn't be all that concerned about the headers, your Transmission pan would give me more concern..

[yellow1098]

I agree with you about the transmission pan but I know how to fix that as that’s a deep pan and I just have to switch to a stock depth one to get more clearance.

Yes the variable is the engine but what can I do besides get custom headers made to fix this? Is there a brand or something that sells a solution?

[scott70]

If the motor mounts were different and lowered the engine you'd see it where the drag link goes under your oil pan. I've seen some drag links actually touching the oil pan.

[firechicken]

Originally Posted by yellow1098

……could the new lower engine mounts have changed it

If you have lower engine mounts that will lower everything attached to the engine.

[78w72]

heads & block should be the exact same dimensions. what are the lower mounts & what is the reason for changing to lower mounts than before? if the mounts are lower that answers why the headers are sitting lower.

other brands of headers do sit different, i have 2" O-port hooker super comps on a slightly lowered 72 firebird & they hang pretty low at the collector compared to smaller hedman D-ports on a 78 T/A that has about the same ride height.

if you dont want to change headers consider getting taller springs or adding a spacer. or run taller front tires.

[PDC]

FWIW - Doug’s D-Port headers give considerably more ground clearance than any other D-Port except maybe the Tribal Tubes Tri-Y headers.

I had expensive Hookers on my D-Port headed car and the passenger side hung so low that it got smashed practically flat. I swapped a pair of Doug’s and never so much as kissed the ground since. And my car had Hotchkis small block lowering springs.

Again, I know I’m talking about their D-Port headers, but maybe Doug’s round ports offer more ground clearance than the hookers?

[yellow1098]

These are the lower motor mounts I installed maybe I need to go back to stock even though it says stock replacement. I will look into the Doug’s also…thank you for the replies

[GTOLou]

Those mounts look fine..

The part you listed is a doug's part number. Round port 1 7/8 - not Hookers (unless Hooker has identical part number).

I've got the same headers on a 76 TA and most of the header is higher, than the lower edge of the frame rail (in other words, headers are tucked up higher to floorboard). If I see you pic correctly - the entire header is lower than the lowest edge of your front subframe rail (2nd gen firebird, I assume).

So yeah, something is major amiss. Recheck you headers for correct manufacturer and part number.

[Formula jg]

You may want to consider cutting of the collector flange and convert to a slip fit with band clamp

[65madgoat]

These work great and what I run instead of traditional header flanges for more clearance:


http://ultimateheaders.com/2018/01/3...rofile-clamps/

[25stevem]

I say you need to look at things physically as you are doing, but with more logic being used.

To me the only place something can be off from the last time everything was bolted up would be where the motor mounts bolt to the block.
This is the 100% only location where since the mounts bolt up perpendicular to the ground, a up and down change in the installed height to the block will not change the V dimension like anything else will if something is not right!

In other words if your new frame mount are made wrong or bolted to the frame off position that can make the V taller or shorter, and either way stuff will not bolt up right.

I hope I am explaining my thoughts clearly?

PS.
You need to be careful because if it is the engine sitting lower then your fan may be only 1/2” away from hitting the bottom of the fan shroud.

[yellow1098]

Thank you guys! I unfortunately have to pull the motor back out so I will definitely check the motor mount situation and post some pics and definitely consider those slip fits…stay tuned