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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Stewart G Griffin on April 02, 2015, 03:21:34 pm

Title: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 02, 2015, 03:21:34 pm

Does anyone know if the v-8 front crossmembers and the 85 and later v-6 front crossmembers are the same for 1/2 tons?

As you know i'm swapping in a 4.3 v-6 where the v-8 once was.  i can't figure out where the new 4.3 mounts go because NONE of the holes line up.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: zieg85 on April 02, 2015, 07:46:53 pm

The V-6 frame perches sit back and use the rear 2 holes on top, there is 3 total.  The side ear bolts to a hole by the top shock mount hole but I will try and put the V-8 ones in Saturday where the V-6 perches came from that I sold you.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 02, 2015, 08:04:24 pm

Yeah, i'm just now getting to it because i had a lot of other stuff to deal with.  i think i'm going to try to drop the engine in tonight with the new mounts already attached to the engine and see where they end up. 

i have a gut feeling that the crossmember IS the same.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 04, 2015, 09:54:40 am

will update soon---almost there.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 04, 2015, 06:33:41 pm

Got it in.  Will post pictures tomorrow.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: zieg85 on April 04, 2015, 06:36:52 pm

Quote from: Stewart G Griffin on April 04, 2015, 06:33:41 pm

Got it in.  Will post pictures tomorrow.

Did the correct holes exist?

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 04, 2015, 10:11:27 pm

Quote from: zieg85 on April 04, 2015, 06:36:52 pm

Quote from: Stewart G Griffin on April 04, 2015, 06:33:41 pm

Got it in.  Will post pictures tomorrow.

Did the correct holes exist?

Ok, the rearmost hole on the crossmember (closest to the cab, farthest from front bumper) DID exist and DID match up.  However, i don't have any other holes in the frame and will have to drill 3 holes on each side.

When you think about it, this is not too surprising as the 90 degree v-6 did not exist when these trucks were originally designed and the engineers did know they'd be using this engine until the 85 model year.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 04, 2015, 10:16:01 pm

What i meant was why would the holes be drilled in a pre-85 frame if the the engineers didn't know they'd be using the 4.3 until 85?

i was mistaken when i said none of the holes lined up.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: zieg85 on April 04, 2015, 10:20:16 pm

Gotcha, I didn't know what year your truck was anyway.

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 05, 2015, 09:51:54 am

It's 83

Title: Re: v-6 and v-8 crossmembers the same?
Post by: Stewart G Griffin on April 05, 2015, 10:37:30 am

As you can see, the rearmost holes on the crossmember do line up:

(http://i223.photobucket.com/albums/dd31/sencraig/000_0465_zpsvzqnjlfo.jpg)

(http://i223.photobucket.com/albums/dd31/sencraig/000_0466_zpsbiimnwcz.jpg)

Now i need to move the engine over to the right say .25" an inch to center it better.  Then i can start drilling.  Engine and trans are connected.

Any tips for drilling into the frame rail?