ENGINE swap problemo's

[75shortysocal]

after pulling the 350 4boltmain, out of my 75 longbed, to put it in my 75 GMC shortbed.


1) the speedo cable connected to the pedal and going through the firewall, seems to be way to long for the different engine... ill be taking some pic's today..... "might just need different bracket bolted to intake manifold?"

2) it doesnt look like the "chevy" 350 out of my lonbed, and the GMC exhaust will match the "chevy" manifolds...possibly.... does anyone know if the match?....its all GM from 1975 so i cant imagine why they would be different...will take pic's today





3) oil pressure sending tube is different.....i need to do some rigging, line coming out of the firewall way to short..


random question:

1) does anyone make a wing window delete? "one window"

[WorkinLonghorn]

Send those pictures.I don't see why this wouldn't be a slam-dunk.

[75shortysocal]

Originally Posted by WorkinLonghorn

Send those pictures.I don't see why this wouldn't be a slam-dunk.

heres a better look...at the exhaust, i dont think they will match my manifolds..

[benoit454]

OK I'm lost, I know you are taking the motor from one and putting it in another truck.

What did the truck you are putting the motor in have in it before? Was it or are they both gas motors?

The exhaust looks like every other manifold setup I've ever seen, only difference maybe in the manifolds, but I'm not sure. if so then the engine you pulled from the truck if it's manifolds won't fit the one it's going into, then what happen to the manfiolds from the truck the motor is going in?

Oil tube? you mean the sending unit? Did the truck the motor is going in have a motor? If so it be alot easier because you could try the original stuff and try the stuff from the new motor going in it.

gmc manifolds and chevy are the same, only difference would be if you had a buick, pontiac, or olds 350 in the other truck.

Speedo cable? You mean the throttle cable that hooks to the carb? if so then maybe the truck had a straight 6. Ours was like that, going from a 76 straight 6 truck with a 300 series 6 cylinder to a 350 v8 it was way too long. if it's a speedo cable that goes to the transmission and works the speedo in dash I have no idea why it be longer?

There are 2 locations for oil sending units, ones above the filter, and the other behind the intake, some have big bulbs back there or just a sending unit the tube hooks to. I'd just buy an aftermarket guage for about $10-20 and it comes with line, fittings guage and all. Then just mount it under the dash or wherever. I've had them under the dash and also made a plate and removed the vent above the heater controls and put in 2 guages there.

Yes they are called one piece window kits.
There's a thing here about group purchase for them, and captkaos had a link on his site for them also.

[75shortysocal]

sorry for the lack of info, i woke up at like 3:30 am and when posting this i was almost completely out of it..lol

the 75 GMC had a 350 in it.....the 75 chevy had a 350 as well...here is the exhast from the 350 engine i took out of the chevy




and here is the "y" pipe that is on the GMC......im not sure if they are the same.




and here is the throttle cable...seems to long for this engine? is this normal legnth of these?



and the oil pressure line im talking about is the one that comes out from the firewall, and connects to the block just behined the intake, near the distributor....its way to short....i guess ill have to rig something to extend the line.....

[neverfinished]

Originally Posted by 75shortysocal

sorry for the lack of info, i woke up at like 3:30 am and when posting this i was almost completely out of it..lol

the 75 GMC had a 350 in it.....the 75 chevy had a 350 as well...here is the exhast from the 350 engine i took out of the chevy


and here is the "y" pipe that is on the GMC......im not sure if they are the same.


and here is the throttle cable...seems to long for this engine? is this normal legnth of these?

and the oil pressure line im talking about is the one that comes out from the firewall, and connects to the block just behined the intake, near the distributor....its way to short....i guess ill have to rig something to extend the line.....

The throttle cable looks about how mine fits. The is a bit of a bend in the line before it gets to the bracket bolted to the carb but it works. It's a bit stiffer than it should be but it works.

As for the oil pressure line you should be able to get some more tubing and a couple of compression fittings to make it reach.

[Slonaker]

I don't think the new engine is a '75 model. I am not sure, but I think a '75 350 would have the dipstick on the driver's side.

There is no way to tell if the manifolds will match up to the exhaust other than to look at the manifolds and see if they are the same on both trucks. if they are, it will work. If they are not, it won't.

If they are not, and both engines have passenger side dipsticks, use the old manifolds on the new engine. If they have dipsticks o two different sides, I don't thing the manifolds are interchangeable.

Slonaker

[neverfinished]

Looking at the pics again I just remembered an issue we had when swapping motor in my brother's '74. The flange isn't different, I think there is a ring that sits down into the flange. The rings may be stuck in the exhaust manifolds. Just pop them out and the exhaust should fit up. We had to pop the ring out of one side when we did our swap. The first picture is the pipes without the ring and the second picture is the pipe with the ring sitting in them. If the exhaust isn't fitting together try looking into the exhaust manifold and see if the rings are stuck in there.

[Pyrotechnic]

If the manifolds and exhaust system are different, just use the manifolds that go with the exhaust system you want to use. Thats what I would do anyway.

Don't count on that fact that it's all 1975 parts you are dealing with. Unless you've owned the trucks from day one or they have very well documented histories, quite a few years have passed where previous owners could have tampered with these trucks and that is often the case.

[Ivan D.]

My throttle cable solution:



I pulled the cable off the housing and cut the housing so only the part that goes through the firewall remains, then I ran the cable through it and left it exposed - the only restriction in cable's movement is the tiny friction due to the firewall guide, which ain't really nothing. Cable works awesome, just make sure you leave a little slack in it when adjusting it at closed throttle.

[75shortysocal]

[Rc 415]

Dang finally done? looks great!

[knightlife]

that motor does things to me, that only a woman should be able to...*shivers*

[Curly86]

You have to watch so of these trucks came with manifolds that don't require donut gaskets on them. I have an 86 Silverado has older model 350 manifolds thd they don't use donut gaskets