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Old 03-17-2006, 07:22 PM   #1
Mechdawg
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HEI hitting firewall???

Alright everyone Im back with more questions. I finally got the 327 stuffed in between the frame rails but now I seem to have a new issue. The 327 I got has a HEI on it and with the engine sitting in its place the very top back of the wires and cap are all the way against the firewall so should I be looking to pull the HEI out and put a low profile ignition in its place or what? I would like to keep the HEI but dont want to damage anything. What do you all think? If it helps Ill try to post some pics tommarrow.
Thanks
Tim
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Old 03-17-2006, 07:25 PM   #2
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Re: HEI hitting firewall???

use hammer make clearance
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Old 03-17-2006, 07:27 PM   #3
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Re: HEI hitting firewall???

You could move the engine up to where it should be, but I hear there is a way to turn the HEI to where it won't hit.
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Old 03-17-2006, 07:30 PM   #4
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Re: HEI hitting firewall???

I think when you use the 6 cyl mounts with v8 you'll have dist fit problems. I know I did. I used a hammer to gain some clearance, but it's hard to make look nice with the engine in. I'm running a Mallory comp9000 now and it's even larger than an HEI.. You can get a small diameter dist from MSD/Mallory.
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Old 03-17-2006, 07:52 PM   #5
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Re: HEI hitting firewall???

Ok so I take it the V-8's do mount further forward then the inline 6 did? problem is it seems if I did move the engine forward the trans wouldnt sit on its mounts right anymore.
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Old 03-17-2006, 07:54 PM   #6
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Re: HEI hitting firewall???

Also if I do move it forward do I need to get different tower mounts?
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Old 03-17-2006, 07:57 PM   #7
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Re: HEI hitting firewall???

What trans are you running, If its the 3 on the tree you cant move it, its rivited to the frame and its not worth it. If its a automatic get the small block towers and slide the engine and trans ahead and all the bolt holes should line up
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Old 03-17-2006, 07:57 PM   #8
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Re: HEI hitting firewall???

yes, you would need v8 mounts im not sure about the trans but i am curious my self
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Old 03-17-2006, 08:01 PM   #9
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Re: HEI hitting firewall???

It was a 3 on the tree but its not riveted in it was bolted to the crossmember. The bolt holes line up right now but can the engine be run there or should it be moved forward?
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Old 03-17-2006, 08:12 PM   #10
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Re: HEI hitting firewall???

he meant the cross member is rivited to the frame
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Old 03-17-2006, 08:22 PM   #11
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Re: HEI hitting firewall???

yeah I thought so I was goina go look but its dark now so Ill have to wait til tommarrow. The only other thing buggin me now is if I do move the motor forward and I cant use the tranny I have then I can get my hands on a saginaw 3 speed but will my drive shaft still fit or will I need to get it lengthened or shortened? Hope Im not buggin anyone you guys have been a great help to me.
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Old 03-17-2006, 08:26 PM   #12
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Re: HEI hitting firewall???

I also cant seem to find small block engine to frame mounts every place Ive checked has the inline 6 or the big block ones no sbc....
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Old 03-17-2006, 08:31 PM   #13
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Re: HEI hitting firewall???

check with teeitup or biskquik or burnsman on the parts board for the
towers there pretty inexpensive
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Old 03-17-2006, 08:37 PM   #14
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Re: HEI hitting firewall???

It is easier to just modify the firewall for HEI. Since it is a stick, changing the mounts/clutch setup/diff driveshaft don't justify the move. Lots of people run them with 6 cyl mounts.
On that note, on my '64 I used tall Edelbrock valve covers and they hit horribly bad. I didn't find out until I had everything done and ready to fire it up(used stockers for mock up). I ended up modifying the firewall for clearance, since I had everything else done already.
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Old 03-17-2006, 10:06 PM   #15
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Re: HEI hitting firewall???

I've done this before knock the rivits on the mount out and move it up the holes are there.Evey thing will line up I did this on my dads 67 back in 72.You will have to use the V8 towers.
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Old 03-17-2006, 11:56 PM   #16
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Re: HEI hitting firewall???

Am having the same problem, my HEI is like 1/2 an inch from the firewall, and i have a 350/350 Auto but if i move the hole engine and trans then i will also need another drive shaft, so i just left the engine the way it is, it good for me. am guessing that that happend because the chassi was for a 6L, i would recommend you to cut a little pice if the firewall and then weld in some thing to cover the hole.
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Old 03-18-2006, 12:26 AM   #17
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Re: HEI hitting firewall???

Another thing to check is the rubber cab mounts, especially the front ones. If the mounts are sagging, new ones will give you more clearance near the HEI.
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Old 03-18-2006, 12:39 AM   #18
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Re: HEI hitting firewall???

Green Machine has answered with what is most likely your problem as I've done a dozen or more 6cyl to V8 swaps putting the V8 in the original 6cyl. mounting position and if your cab mounts are good you should have approx. 1" clearance between the distributor cap plug wires & firewall.
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Old 03-18-2006, 12:42 AM   #19
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Re: HEI hitting firewall???

I have the same problem and also will correct it by working the firewall slightly with a hammer. I suggest marking the area where the two or three wires make contact with the firewall. With the cap removed, you will know exactly where to create more clearance. I am also going to take Green Machine's suggestion and check the cab mounts. I don't want to consider relocating the engine because I have the transfer case to also deal with.
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Old 03-18-2006, 01:00 AM   #20
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Re: HEI hitting firewall???

BTW - 4wd models all used the "6 cylinder" position whether they were a SB or 6 banger, they were all installed in the rear position.
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Old 03-18-2006, 01:18 AM   #21
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Re: HEI hitting firewall???

mechdawg... check this post, I asked the same thing... you can see where the PO had the motor mounted, it was a v8. The truck was originally a v6

http://67-72chevytrucks.com/vboard/s...d.php?t=192765
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Old 03-18-2006, 01:27 AM   #22
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Re: HEI hitting firewall???

I have a V-8 in the 6 hole w/HEI and enough clearance. No firewall hammering here. Listen to GMC Paul and GreenMachine...your cab mounts should be checked and the spacer washers for the front of the cab.
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Old 03-18-2006, 01:54 AM   #23
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Re: HEI hitting firewall???

I put a one inch body lift on my Trazer I'm building and have all kinds of room now. It was hitting before. Definitely check front cab mounts. Rick
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Old 03-18-2006, 12:01 PM   #24
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Re: HEI hitting firewall???

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Size:  92.5 KBI have some new energy suspension cab mounts on the truck right now. But I will go out there and check maybe I could raise it up some. Here are a few pics of the progress so far. I did pull the engine and lightly hammered and touched up the firewall. The HEI isnt as bad now but the passenger side valve cover is less then a 1/4 inch away from the firewall.
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Old 03-18-2006, 12:13 PM   #25
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Re: HEI hitting firewall???

Ok I went out there and measured my front body mount pucks measure right at 1 inch thick. Is this correct? Or did I end up with the wrong set. Can anyone out there give me the correct thickness for the front and rear pucks?
Once again its a 67 2wd short wheel base. Thanks again guys.
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