Engine Placement/Mounts???

[jackitup300]

I have a 70 chevy 1/2 ton 4x4 lwb body on a 72 4x4 3/4 ton lwb frame. the 70 had an inline 6 in it but I'm not sure what the 72 had in it. anyways, I have a small block in the truck right now with a th350 and a np205. It has tall valve covers and the outside edges rub on the firewall as is. I had a HEI distributor in it and that also rubbed on the firewall. The fan is a good 6 to 8 inches from the radiator. The transfer case cross member fit on the original holes and both stock drive shafts fit fine when I built the truck. My plan is to go to a solid roller 396 big block and I can not see how it would fit without modifying the firewall. I know these trucks came with big blocks but I don't understand whats wrong in mine truck for a big block to not fit. There are holes to move the engine cross member forward but they are only on the top of frame and even if I did that plus drill holes in the bottom, my front drive shaft would be too long and my rear would be too short. Looking for some input please. These are the pictures I can find right now to show my situation. thanks.

[too much stuff]

No big blocks came in a 4x4 in these years. Also, no hei distributor or tall valve covers from the factory. It sounds like your engine is in the right spot. It is just a tight fit with the components you have. If your cab mounts are bad, that will make things worse.

[jackitup300]

ok thank you. Would I still have problems if I had a 2wd cab? or is it because of the 4x4 frame? Did they only fit big blocks in 2wds from 69-72? thanks.

[too much stuff]

I believe you would still have the same issues with any cab. I put a big block in my 70 about 15 years ago. I had to grind one edge of a valve cover and beat in the firewall a little bit for the hei. I also used stock exhauust manifolds from a 77 pickup and set it on the original 350 mounts. It took some work, but nothing real major for the swap.
And yes, the big block was from 68-72 in 2wd only.

[jackitup300]

ah ok thanks I understand. I think I might be able to get away with it with a 3" body lift. otherwise it's not a big deal to mod the firewall. thanks alot.

[Newtz67]

You can fit the big block or small block on the front mount holes and they will line up with the holes in the cross member. I've seen it done many times. Check out my thread. The only issue you may have with mounting in the front holes is header clearence, other than lengthening your drive shaft and moving tranny mount. Get the right headers and you'll have no problem. If you have any questions let me know.

[OJ1988]

I can only speak from 2wd experience, but on mine,

it was an inline 6. The v8 mounts place the engine about 2 1/2" forward than the inline 6 position.
I have a small block in mine now using the 6 cyl mounts.
I am running a large cap hei and have enough room to place my hand between the cap and firewall. I have short valve covers but should have room for tall ones. I had to run an electric fan because the engine sat so far back.

To me it sounds like yours is mounted in 6 cyl mounts.
Your description of the holes on frame match mine as well.
Sounds like you may want to look over cab and core mounts as well.
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