P-30 Engine swap

[Bfrank]

I am about to swap out my old and tired 454 for a remanufactured longblock 454 from S&S Engines. Can anyone who has done this chime in with any advice or tricks to help make the swap go smoothly. I am also installing a 13 clutch 700 R4 transmission and a set of hooker hedders. I would love to hear from anyone that has
done this or anything similar. It's going to be a big job and is going to be time consuming. It already looks as if I need to grind off some buck rivets that hold the front bumper to the frame of the coach so I can get the old gal out the front of the doghouse. The coach is a 1979 Classic 24 ft Excella. I have dreams of a polished coach with a strong 454 engine that has overdrive and hopefully a little better fuel milage than the 5 or 6 I was getting.

[RUSSELL]

Hi,
Why not buy a new long block fro GMC?The price schould be the same and it has 50k warranty on it.
I have taken out motors out of my old tool truck, The C30 frame schoul be same as your AS. Remove all front cover and crome. I did not have to take oo the bumper.
Remove radiator and the rest of sheet metal.
When yu are buying a trany try to get an Alison. It is better than the 700-4R. Alisons are build for heavy duty and have 4 speed and a lock up converter. I do not know if you vehicle computor will habdle an Alison but if does that is the only way to go.
Regards from Russell in sunnny Tucson Az.

[guy99]

Originally Posted by RUSSELL

Hi,
... Alisons are build for heavy duty and have 4 speed and a lock up converter. I do not know if you vehicle computor will habdle an Alison but if does that is the only way to go.
Regards from Russell in sunnny Tucson Az.

Alas, no computer in a 1979.

[RUSSELL]

You Are right, but there companies selling after market , computers which are just work greate, it all depend on how much money you are willing to invest and if you want better milage.
Russell in Sunny Tucson Az.

[HowieE]

The 700 R4 is not know for lasting a long time while pulling in OD. The idea of an Allison would be a great idea. 1979 vehicals most likely used a throttle position cable to control the trans rather than a computer so you should not have a computer issue to deal with.

If you are going with the 700 my additional comments. On my 1987 1/2 ton Suburban with a 700 R4 I install a Gear Vendors splitter behind the trans set up as an OD and towed in 3rd gear Over to overcome the towing issue. Also had the trans redone with extra clutches. That 1/2 ton towed my 34fter cross country and the truck just went out of the family with over 250,000 miles on it.

[overlander63]

When you take out the old engine, and put in the new one, remove the intake manifold first from the old one, and put it on th new one after it is inside the engine compartment, it will give you more room to work. Also, if you can get to them, remove the engine mounts beofre removing the engine, for the same reason.
The 700R4 uses a lockup torque converter, which needs 12v fed to it. No real computer stuff should be needed.

[bkahler]

Originally Posted by RUSSELL

Hi,
When yu are buying a trany try to get an Alison. It is better than the 700-4R. Alisons are build for heavy duty and have 4 speed and a lock up converter. I do not know if you vehicle computor will habdle an Alison but if does that is the only way to go.

Russell,

If switching to an Allison transmission which one would be appropriate? We have an Allison MT643 sitting on the shop floor that We've been hanging on to in the hopes of using someday in a conversion of the 454 in our 310 to a diesel.

Thanks,

Brad

[Bfrank]

The most I'll ever be towing is a small trailer with a golf cart. Remember this is a 24 ft classic so hopefully the 700 R4 will do the trick. this tranny also has been built for towing it has 13 clutches instead of 9. I tried to buy a GM crate motor but was told that they no longer sold new blocks. I would ask whoever has done this kind of project if they had to remove the motor mounts. I already believe that I will have to grind off some buck rivets that hold the front bumper on so it can be removed to get the engine out. Would love to hear from anyone who has acutually done this

[GlenCoombe]

If you remove all the front end grill and access cover you should have enought height once the engine is brought forward to clear without removing the bumper. Also once you have the motor moving you can get at the oil pan bolts so as to remove the drop down pan giving you more wiggle room.
You can make the block pretty lean by removing all the accessories as mentioned earlier.
Going slow and having lots of eyes on the margins will make the job that much easier.
Let us know how you make out.... oh, and photos would be great as the project progresses too.

[Bfrank]

I will try to document the surgery and thank you for the advise. I had already decided to pull the manifolds and will have to pull the a/c compressor for height clearance. Iv'e got a tow motor to use but I am going to have to fabricate some kind of extention for the forks so I have the reach that I need to get over the carb. I'll pull it and then use a short chain to lift the block up. Hopefully I can remove the engine and tranny as one unit, at least that's the plan.

[GlenCoombe]

Wow...stop right there.

Rent or buy an engine hoist to do the job it was designed to do. You'll have much better control over the process.

Remove all accessories you can get to once the rad is out.

Once the engine is disconnected from the tranny you can just drop the transmission straight down. All at once is a bigger mass to negotiate. Not a deal breaker though.

Pull the oil pan, carb, and get all the exhaust components out of the way prior to starting. Hopefully you are coming back with headers.....

You'll only pay about $150 for a hoist and get so much out of it. Much better control of the movements too.