66 GMC Big Block upgrade

[Gunster89]

ok so i dont wanna sound like i dont know what im doing im 23 im still learning and i will listen to any advice that anyone has for me ive learnt I have a 66 gmc it has the 292 straight 6 in it im not sure exactly what trany I have but its a 4spd with granny and has a posy rear end I am removing my straight 6 and gettin ready to get a big block im curious what modification needs to be done to fit it in will another bell housing work or do I need a bigger tranny does anyone have any recomendations on what wiring harness to use Im not rich after a good harness but cost effective also id like pros and cons to an automatic with a shift kit in it verses a starndard shift like i have atm and recomended transmitions
basically im after a wow factor when i pop the hood thank you for the information ill post pics as I do my progress atm I am removing my engine and getting ready to paint the engine conpartment and id like to install the wire harness while the engine is out to try to hide my wires and any input on how to hide my wire would be much appreciated and any other info that you may think I could use is also welcome Ive never done an engine swap and im doing it all myself like I said all the advice you would like to ride ill take to knowledge ty again

[60-66]

Here's a few pictures of the installation I did on my old 65 GMC. I used the 68 69 70 Chevy or GMC BB frame mounts and a stock 63-66 Automatic Cross member. NO trimming or mods to the firewall at all, just a simple bolt in and go.You do want to test fit everything first with the valve covers your going to use as it does get close to the firewall. I used headers but 68 69 70 truck exhaust manifolds and PS brackets all bolt right on with a short water pump. I increased my stock rad to a 4 core. Also ran a TH 400 but most of the overdrive trannys fit also.Also I had my friend at American Autowire make the wire harnesses for the truck, all you do is call them and tell them what your building and they know what to ask you. Try Don Bock over there, HE KNOWS these trucks and wiring them.Keep us posted, love to see your progress. Jon

[66farmer]

I used a BB and th400 out of a 78 truck.

Engine perches are tubular
Motor mounts are 70 Vette
Trans mount Early Classic
Headers Sanderson
I had to adjust the Firewall just a little for the vave covers. I wanted the engine as far back as I could get.

Hidden wire conduit HomeDepot

[Gunster89]

thank you for the info i greatly appreciate it what size exhaust you guys runnin and are you runnin shorty headers or reg?

[hd74]

used the same motor mounts and trans cross member as 60 66.i used stock manifolds with 2 1/2 pipes on mime 1963 gmc suburan

[Captainfab]

If you want a manual trans with a big block, converting to a hydraulic clutch will be the simplest way to go. I believe the majority of the guys that have went big block, have converted to an auto trans.

[19GMC66]

60-66...very nice looking GMC..Wow!
Posted via Mobile Device

[Gunster89]

ty was also wondering if the different brand headers make a difference or if im just paying for a name? and im wanting to go with a 3" exhaust and come out right behind the front tire any problems with that?

[redneck6]

i used 78 perches and motor mounts . had to notch top rail .. used cpp crossmeber for tranny . used hydro for clutch and tranny is a sagninaw 441 4 speed . headears are super comp for a chevelle fit but not perfect .. if ya want or need pics i ll try and post them. my 454 recently took a crap and got a 61 small journal 327 in it now same mounts and all got to love chevy interchange ...

[padresag]

Originally Posted by redneck6

i used 78 perches and motor mounts . had to notch top rail .. used cpp crossmeber for tranny . used hydro for clutch and tranny is a sagninaw 441 4 speed . headears are super comp for a chevelle fit but not perfect .. if ya want or need pics i ll try and post them. my 454 recently took a crap and got a 61 small journal 327 in it now same mounts and all got to love chevy interchange ...

hey was that 61 small journal an experimental engine?
ron

[kieth]

Originally Posted by 60-66

Here's a few pictures of the installation I did on my old 65 GMC. I used the 68 69 70 Chevy or GMC BB frame mounts and a stock 63-66 Automatic Cross member. NO trimming or mods to the firewall at all, just a simple bolt in and go.You do want to test fit everything first with the valve covers your going to use as it does get close to the firewall. I used headers but 68 69 70 truck exhaust manifolds and PS brackets all bolt right on with a short water pump. I increased my stock rad to a 4 core. Also ran a TH 400 but most of the overdrive trannys fit also.Also I had my friend at American Autowire make the wire harnesses for the truck, all you do is call them and tell them what your building and they know what to ask you. Try Don Bock over there, HE KNOWS these trucks and wiring them.Keep us posted, love to see your progress. Jon

Did your GMC end up in Europe, I think I saw pictures of it over there...?

[60-66]

Hi Kieth, Im really not sure. Last I saw the truck it was on EBay at a shop in Chicago. Heres a picture of what it looked like with the billet wheels I later put on it.

After this picture the new owner put a 572/4L60E combo, changed the front cloth seat to leather and changed the GMC lettering on the grille from the red insert to green. There were a few other small changes. He then traded it for a boat but I think it stayed in Chicago for awhile then back on EBay again, so it could very well be over there. If you see it somewhere let me know. Thanks,jon

[60-66]

Originally Posted by 19GMC66

60-66...very nice looking GMC..Wow!
Posted via Mobile Device

Thanks 19GMC66, thats one truck I hated to get rid of for sure. I since found a black 65 GMC Short fleetside big window to take its place though. Jon

[60-66]

Originally Posted by Gunster89

thank you for the info i greatly appreciate it what size exhaust you guys runnin and are you runnin shorty headers or reg?

I ran the same header as 66farmer. Sanderson makes a header that doesnt hang so far below the frame and has nice thick flanges . 2 1/2 inch pipes to the mufflers. Jon

[Gunster89]

Originally Posted by 66farmer

I used a BB and th400 out of a 78 truck.

Engine perches are tubular
Motor mounts are 70 Vette
Trans mount Early Classic
Headers Sanderson
I had to adjust the Firewall just a little for the vave covers. I wanted the engine as far back as I could get.

Hidden wire conduit HomeDepot

I went to home depot couldnt find the hidden wire coduit you have in the picture the stuff they showed me was the cheap plastic wire loom stuff and what is the plastick pice you are usin for a fire wall gromet?

[Gunster89]

ok so i have been thinking I havent found a block yet im thinkin that it may be more cost effective to use my 92 camaro as a donor and take the 305 with tbi outta it and dump it in the trunk till i can better afford to build a big block the camaro has a hydraulic clutch that i could use in the truck idk if i could use the rear end and the front steering or not for the fact it has 5 lug disk all around also was thinking i could take the gas tank outta the camaro and it would fit under the rear of the truck idk what do you guys think? motor has 120 miles on it but ive smoked everything ive raced with it strong motor strong tranny strong rear end small block isnt the permanent motor for the truck but if I do it ill keep the motor in it 2 years and save to build a sweet big block

[Captainfab]

The rear end and steering from the Camaro won't work for your truck. The engine and trans will though.

[redneck6]

Originally Posted by padresag

hey was that 61 small journal an experimental engine?
ron

sorry 62 sj 327 . allthought i have read on a few places like mortech and such were it is a 61-62 block . so very may well be a exp motor .. but good looking out .

[Captainfab]

Were you looking in the home electrical section? What 66farmer used is called liquid tite flexable conduit.

Originally Posted by Gunster89

I went to home depot couldnt find the hidden wire coduit you have in the picture the stuff they showed me was the cheap plastic wire loom stuff and what is the plastick pice you are usin for a fire wall gromet?

[backtowork]

pm sent....