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CorvettesLessons
Learned from 700R4, Hedman Headers, DART Iron Eagle
Heads

TedH
Senior
Member

1758 posts [100%]
Tampa FL

Lessons Learned
from 700R4, Hedman Headers, DART Iron Eagle
Heads

5:29
PM 5/19/2002

Well, now that I installed a set of Jet-Hot
coated Hedman Hedders after my 700R4 and DART Iron Eagle Head
install, I have a few items to share for those considering a
Hedman Header purchase:

Forget using the PF35 'long' oil filter. The Hedman's rest
up against the bottom of it (I had to drop the driver's header
to remove the PF35). I have since gone back to using the PF30
that the car came stock with. Gained about 2" clearance
between the header and filter.

TH350 and 700R4 trans lines run TOO CLOSE to the header
collector. I mangled my lines just to find that starter
installation required even more bends in the lines. Now they
don't remotely resemble the lines that I started out with.
Just purchased a $10 tube bender and am going to pull the
lines out in hopes of salvaging/re-bending them.

The Hedman header collectors stop just forward of the
aluminum case of the transmission and are way to close to
either side of the 700R4 for my taste. If I went with straight
pipes, I'd be super-heating the transmission pan on the
passenger side and melting the rubber sleeve that covers the
gear selector on the driver's side of the trans case. I'm
hoping the muffler shop can bend 2.5" pipe at the collector to
get some space on both sides of the tran. If not, I may have
to go back to the 2" exhaust manifolds ($500 spent on those
headers...). Until I get to the muffler shop, I'm running
straight pipes back to the differential area (sound like Dale
Earnhard'ts #3 when I goose the engine).

In order to get the passenger header in, you have to
disconnect the idler arm from the right frame rail and drop
the center linkage. Also helps to remove the starter since,
once the heads are in, it's a tight fit on the passenger side
of the engine. Also pulled the dipstick and tube until I
sorted out the header.

Forget reusing the metal sparkplug covers. I retained the
'v' shaped covers on either side of the lower crankcase so
that I could run the wires to 1-3 and 2-4 without worrrying
about the header pipes. But as for the metal covers that the
pairs of plugs (1-3, 5-7, 2-4 and 6-8), there is no room (no
big surprise). My DART heads are straight plugs and I found
that the 90 degree plug boots work fine. I just had to find
creative ways to keep the wires from resting on the header
pipes.

The heads take 3/8" NPT fittings and my old heads used the
1/2" fittings. Caused me to buy those recessed allen-head
chrome plated brass plugs for the heads and then I moved the
1/2" heat sender to the left front of the intake manifold
(Edelbrock is kind enough to leave several 1/2" and 3/8"
tapped holes in the 3701 EGR intake manifold).

I tried Lars' lifter pre-load instructions but I still have
noisy lifters. May be wear and tear (less than 10k miles on
the rebuild) or my lack of experience in knowing when I reach
0 lash using the static method (most likely the latter).
Regardless, the valve covers will come off this week and I'll
be getting the headers nice and oily as I adjust the noisy
rockers...

Lars did an excellent job of rebuilding my q-jet. About
$175 total expense including shipping it off to him.

The DART heads appear to work fine. I installed them with
little incident. I found a clearance problem when attempting
to torque the 'submerged' headbolt (that bolt that will spend
its life submerged in motor oil just rearward of the #8
exhaust valve or just forward of the #1 exhaust valve). I used
the 5/8" head bolts that are available from FelPro. The head
casting has a bit too much material around the headbolt. Not
sure if ARP offers a smaller head on their head bolts or not.
I got around it using a 'Ford tool' (hammer) to force a 5/8"
socket onto the bolt heads (and to stay there while I torqued
the final 65 ft lbs setting).

I found that DART machines the valve cover rail flat and am
hopeful that this creates a flatter/larger sealing surface for
the valve cover gasket (appears to).

When I initially tried installing the alternator and
bracket onto the DART heads, I suspected there was an
alignment problem. Later found that I was trying to line up
with the a/c compressor belt. Once I sorted the belts out, I
found that the pre-tapped holes in the heads work fine with
the stock alternator mounting hardware (no modif's req'd).

Installing my a/c compressor (short style) required
grounding off a portion of that a/c mounting bracket (that
bolt hole that once attached to the front exhaust manifold
bolt). With the header pipes, Hedman just recommends sawing
off this bolt hole as the compressor has plenty of other block
attaching points (I counted three) to keep it stable.

I was worried that the new DART heads would be way too
heavy (more than my 882's for sure!) to wrestle onto the block
decks. Well, once I had a good hold on the top and bottom of
the heads (length wise) I 'curled' them onto the deck surfaces
and aligned them with the two dowels. Once on the dowels, I
had two head bolts with #2 permatex at the ready to start
(didn't want them to drop off).

Get the moroso starter shield from Jegs. $21 and it should
help to prevent heat soak from the header heat.

While you are adding to your toolset for a project such as
this, go to Sears and get the remote starter switch. It saved
me using the ignition and running between my flashlight and
timing mark and the ignition. I was able to attach the two
leads to the starter and easily bump the starter around to TDC
for the distributor drop-in as well as to advance the engine
every 90 degrees when setting lifter preload (once you get to
the #1 cylinder starting point that Lars describes in his
instructions). Having the remote starter switch for this alone
was worth the $12 that I spent on it.

If I recall any more bits of wisdom from this installation,
will update this thread.

[Modified by TedH, 7:35 PM
5/19/2002]
_______

TedH
'80 Garnett Red
Metallic/Pearl Base Coupe & '01 Pewter Coupe - Always
Waving!!!

gdh
Senior
Member

622 posts [100%]
Orangeville
Ontario

Re: Lessons Learned
from 700R4, Hedman Headers, DART Iron Eagle Heads
(TedH)

5:59
PM 5/19/2002

Thanks Ted I just am about to install the Dart
IE's s well and have been waffling between putting on my new
'69 style sidepipes that I purchased in Jan, or keeping my
dual setup up but running 2.5" into the Dynomax Ultra Turbos.
Did you notice a marked performance improvement with your new
heads and headers.
_______

72 LT-1,
ZR-1
4-speed
mille miglia convert.
after 30 years,
soon to have heart surgery

TedH
Senior
Member

1758 posts [100%]
Tampa FL

Re: Lessons Learned
from 700R4, Hedman Headers, DART Iron Eagle Heads
(gdh)

8:10
AM 5/20/2002

I gotta re-route the trans lines and install
the starter heat shield before I make the run to the muffler
shop. I haven't driven it yet so can't comment much on the
performance improvement. With the carb recalibration by Lars,
headers and the heads, I'd be expecting another 80rwhp since
I'll finally feel the benefit of all of the other power adders
that I had put on but had been running through the restrictive
882 heads and cast iron exhaust manifolds (Energizer cam,
K&N filter, Performer intake, 9:1 hypereutectic pistons,
dual exhaust). The IE's also have 72cc chambers so I should
also get a bit more power due to the increased
compression.
_______

TedH
'80 Garnett Red
Metallic/Pearl Base Coupe & '01 Pewter Coupe - Always
Waving!!!

MotorHead
Senior
Member

967 posts [100%]
Mississauga, Ontario,
Canada

Re: Lessons Learned
from 700R4, Hedman Headers, DART Iron Eagle Heads
(TedH)

9:33
AM 5/20/2002

Ted try this if you have an old set of valve
covers, much cleaner. From what you described when setting
intial lash I would suspect you are out of spec on a few
lifters.
I simply backed of the lifter until I heard it
click then tightened 1/3 a turn ( some said 1/4 and some said
1/2 )

Runs like a clock now, BTW don't dirve it too much until
you do this.

[Modified by MotorHead, 11:34 AM
5/20/2002]
_______

1980 400+HP Numbers Matching
L48 4sp, Sportsman II heads
Flat top pistons, Comp Cams
270H MAGNUM (1.6 rockers), 10:1 CR
Holley 750 DP
Mechanical, Edelbrock RPM Air Gap , Dynomax Headers
2.5 in.
true duals to MagnaFlow SS,
BFG 295,265's 50 Series, New
paint, New Leather seats

TedH
Senior
Member

1758 posts [100%]
Tampa FL

Re: Lessons Learned
from 700R4, Hedman Headers, DART Iron Eagle Heads
(MotorHead)

9:41
AM 5/20/2002

Excellent idea! Was wondering what to do with
that spare set of chrome valve covers hanging on the garage
wall!!! Although, I sure hate to ruin a good set of covers for
this activity. I'll think it over.
_______

TedH

'80 Garnett Red Metallic/Pearl Base Coupe & '01 Pewter
Coupe - Always Waving!!!

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