Motor mount position for HEI clearance

[chas350]

OK guys, question for ya's

Our 71 K10 came original with a 6 cylinder and the SM465 4 spd and NP205 the PO changed it out to a 283...

We have put in a 350 and are still using the SM465/NP205. The cab is off the frame now for a frame up resto.
My question is, should the motor mount towers be in the front set of holes or the rear holes to have clearence for an HEI distributor with a 350?
It is currently installed in the rear holes (no cab yet, remember) and I have about 6" +/- from the clutch fan we used and the radiator. I do not have a shroud for it yet to check clearance. The rear tranny cross member is bolted in along with the transfer case torsion mount, so I think I am OK.
But I remember reading somewhere about HEI clearance issues with the firewall, maybe here, dont remember.
sorry for the book version, never could keep things simple

Can anyone clear this up?
thanks,
chas

[Palf70Step]

I am pretty sure all the 4WDs were mounted in the rear holes, 6 or 8.

I mounted my 2wd in the back set and I have plenty of room for the factory HEI. Not a whole lot extra mind you, but plenty of room none the less.

[68GMCCustom]

my V8's mounts are in the rear holes and my dizzy is tight to work on... but there's just enough room.

[bryanw1968]

From what I know.....

The 250 6cyl is mounted on the back two mounts. The bigger 6cyl(I think the 292) is mounted one motor mount rear and one on the front holes. When I bought my truck it was a 6cyl but had been converted to a V8 and they used the original 250 mount holes and the motor is WAY towards the back. It works but it is a giant pain in the ass to mess with the distributor. Also the bell housing bolts are almost impossible to get to. I would strongly suggest setting your motor on the front mounts in any V8 situation. However, the only good point to having your V8 set back on the rear mount holes is that you have a better weight transfer in as far as a drag race setup goes.

[chas350]

Thanks guys, now that I think about it, Im not sure if I can change it because its a 4x4 with a transfer case.

chas

[Sport/Truck]

Originally Posted by chas350

Thanks guys, now that I think about it, Im not sure if I can change it because its a 4x4 with a transfer case.

chas

I don't think you can either. Your entire set up is set that way from factory IE:
Longer radiator shroud, transmission cooler lines, longer power steering hoses & your drive shafts will be shorter. And probably a few more things that I didn't mention as well.
s/t

[68,69 K20]

Originally Posted by Palf70Step

I am pretty sure all the 4WDs were mounted in the rear holes, 6 or 8

Yep, my 69 K20 was originally a 292 I-6 truck. Just swapped to a 350 and mounted it in the same spot as the I-6 and it fit fine.

I don't recommend moving it forward to try and gain clearance for an HEI. Mount it where it should be, the HEI will be a tight fit, but it will fit. Both of mine have sat tight to the firewall.

[68,69 K20]

Originally Posted by bryanw1968

I would strongly suggest setting your motor on the front mounts in any V8 situation.

That may work ok with a 2wd, but not a 4wd like he is running. The gains made for HEI clearance will be quickly nullified by driveshaft issues among other things.

[Senator350]

Originally Posted by Sport/Truck

I don't think you can either. Your entire set up is set that way from factory IE:
Longer radiator shroud, transmission cooler lines, longer power steering hoses & your drive shafts will be shorter. And probably a few more things that I didn't mention as well.
s/t

Never noticed that the shrouds were different depths between my 2wd and 4wd.

I've never heard anyone tell of dizzy clearance issues, only big block clearance issues. My dizzy is tight to the firewall, but it's less annoying than most other work i do under the hood.

[chas350]

Thanks boys!
sounds like we are ok.


This site is awesome!
Soon as Im back to work with some money Ill be upgading my membership.

chas