View Full Version : Buying a 454 to run on gasoline!

07-07-2013, 11:27 AM
I found a 454 on propane and going to go do a compression test\oil pressure test on it this week. Seller says gas carb will bolt on to it. Any good ideas re a propane 454 compression & oil pressure specs?

07-07-2013, 12:28 PM
If motor was built for propane , could have a high CR 10.1 or 11.1 . So 94 octane fuel , timing should be different but easy fix .

FU Toolbag
07-07-2013, 11:59 PM
If it was built for propane just keep running it. If its set up right you get more power just not as high a rev. On the other hand most people just toss a propane mixer onto a stock motor and go so switching back is just as simple.

07-08-2013, 09:26 AM
Sounds good. Yah seller may sell me entire truck. Its a 1985 chev 1 ton dually with front dana 60 (he says HD60? It was fixed at one time and axle replacement had different ?larger? option??). It has sm465 and np205. Cab looks really good yet going to go look at it Tues morning to really check cab out, like cab mounts etc. I seen the front dana 60 under it and it looks similar to dana 60 under my 81 Jimmy. Going to check comp., oil pressure etc. Its just a cab chassis, no box. He wants $2500 for it so after I look at it better maybe counter offer?? I figure just put cab and propane 454\sm465\np205 on\in my 81 Jimmy frame! 81 Jimmy is really rotted out. I figure its a fair price considering all the goodies it comes with!! I can use 1 ton frame and duallie wheels/dana 60 for other firewood truck project!

07-08-2013, 09:43 AM
Oh forgot to mention $2500 includes a 2nd 454 in parts. Block bored 40 over with 40 over pistons ready to be installed! New cam, new gasket kit etc. Offer sounds good on the phone ;)

07-16-2013, 02:01 PM
I think 2500 is too much. 454 in parts has surface rust on everything. I assume honing will fix-up cylinders yet I'd have it checked for cracks too. Crank has surface rust but no pitting. Propane 454 runs good! Clutch slave is shot. Rear brake line from diff not connected. I was hoping to drive it home for $2500. Seller thinks 2500 was fair price before, maybe offer him $2000? I know if I part it out its worth paying 2000. Cab mounts rusty here and there. Paint flaking yet looks like no rust holes. Rockers, doors, fenders, rest of cab nice and solid...

07-16-2013, 02:02 PM
Oh... if converting back to gas I`d add a mechanical fuel pump and I guess a 350 pump rod will be too small to run off 454 cam??

07-16-2013, 02:03 PM
I think I'd just keep it on propane. Do fuel tanks expire like the bbq tanks lol??

07-16-2013, 07:53 PM
Its worth $2500 in parts so pretty fair price that SM465 and NP205 should be 32 spline round adapter 205 which was only found in 1 ton trucks if its original

07-17-2013, 09:40 AM
Its worth $2500 in parts so pretty fair price that SM465 and NP205 should be 32 spline round adapter 205 which was only found in 1 ton trucks if its original

Thanks! The np205 has a pto on the side of it too so I guess thats a bonus too! Thanks for the input 85chevy!!

07-20-2013, 09:05 PM
Buy immediatley

07-31-2013, 06:53 PM
I went to give seller 1000 down Monday yet he said bring all 2500 when I pick it up at end of August!! Thanks for the tips! I'll post pics when I get it home....

09-06-2013, 08:27 PM
Bought truck, will post pics soon! Extra 454 has "HI PERF PASS" casted into end of block. Casting num 3999289 GM10T, AND ON SPOT FRONT PASS T0619TRH T41547287. Crank has 3MR 010 03073 STAMPED ON IT AND CAM HAS 3041 Stamped on it. Heads 336781, intake 336789. So hope to post pics soon...

09-22-2013, 02:46 PM
Well finally some pics. Truck is registered as a wrecker...

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/85Chev4x41ton800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/85Chev4x41ton800x600.jpg.html)

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/85Chev4x41tonrear800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/85Chev4x41tonrear800x600.jpg.html)

Heres pic of 454 block I got with above truck. Truck came originally from Surrey. This 454 in parts was found in a shop that guy found after he bought the place. Original owner was into racing vehicles in the Lone Butte area. 454 looks like its ready for a rebuild yet since I have no history on it I guess I should take it to a rebuild shop to check for cracks etc and how worn cylinders are? What is that shaft for in camshaft hole? Fuel pump rod? I wonder what HI PERF PASS means casted on block?

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454block800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454block800x600.jpg.html)

The heads came with no valve train or head bolts.

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454heads800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454heads800x600.jpg.html)

Does the low budget engine rebuild mean exchanging older heads like these for reconditioned rebuilt ones? I'm told that heads Unlimited in Surrey is good place to deal with.

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454headvalveseats800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454headvalveseats800x600.jpg.html)

It came with 8 pistons and con rods...

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454pistons800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454pistons800x600.jpg.html)

Crankshaft has a rebuild tag on it but journals have collected rust...

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454crank800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454crank800x600.jpg.html)

Anyone know what these marks mean? 3MR 010 03073

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454crankstamp800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454crankstamp800x600.jpg.html)

I guess crankshaft should be taken in and professionally polished and measured?

http://i65.photobucket.com/albums/h213/godtool/Projects%202013/454rustycrank800x600.jpg (http://s65.photobucket.com/user/godtool/media/Projects%202013/454rustycrank800x600.jpg.html)

I got lots of other parts, most of the push rods, most of the rockers, oil pan, valve covers, camshaft, balancer, but no head bolts, valves, etc. What does a guy do? Find another complete 454 for bolts etc... I've seen cheap 454s with no history, not running, for couple hundred bucks... Thinking I may rebuild it over the winter or have a shop professionally do it. I have rebuilt an engine lol before yet I need to buy micrometers, t-guages, etc. I've been told of some good rebuild shops in Port Kells, and a couple around here...