NEW TO SITE! Engine swap questions

[PLYONS11]

Hi all,

I have recently acquired my late grandfathers 1963 GMC 3/4 ton long bed as a project. The truck has the original 305 V6 with 43k miles. Though this is cool engine, it isn't really practical for what I want (horsepower). The truck is 2wd and currently has 8 lug hubs. Plan to also do a disc brake conversion and swap out for 5 lug axels and spindles.

I know the answer is probably already out there in some thread, but I'm just not finding it. I would like to drop in a 383 or 496. I'd prefer a 496, but I find conflicting info on fitment. Is it possible to drop in a 496 without fabrication. I have little to no experience with fabrication, nor do I have the tools or space to do it. I can turn a wrench all day, but I'm not willing to attempt frame modification and can not afford to have it done. From what I understand a SBC will fit without any modification, but I really want a 496.

My plan is to keep it carborated or possibly using an EZ EFI or like product for fuel injection.

Any/all insight or suggestions would be appreciated. This is my first GM (don't hold it against me, I have multiple family members that work for Ford.)

I'm also open to suggestions on the trans to put behind either of these engines.

[Captainfab]

Welcome to the forum

A big block is fairly easy to do. It somewhat depends on which trans you plan to use. An auto is easiest. If that is what you want, I would recommend either a TH400 or 4L80E with the latter being my preference. With a manual, it is easiest to convert to a hydraulic clutch. There are several trucks here on the forum with big blocks and just about everyone has their own idea on how to make it work. There is also a thread or two on just big block swaps. Check out member 60-66's latest '63 project with a big block. It is titled 'Finished my 1963 SWB'.

[60-66]

Welcome to the Forum !!!!

Heres a few shots of the frame mounts that Captainfab is speaking of. These are stock big block frame mounts from 1968-1971 Chevy and GMC trucks. They are a bolt in and move the engine forward enough so your not banging up the firewall. You will need to trim the upper edge of the frame back a little, they did this on the 68-71 frames also from the factory. You can see what I did in the close ups of the mount. You will also need to move your trans crossmember, I just bought one on-line aftermarket and redrilled the holes. Very easy swap, these mounts also give you more clearance for stock exhaust manifolds. I ran Sanderson headers here with no trimming or clearance issues.

[PLYONS11]

[QUOTE=60-66;6704526]Welcome to the Forum !!!!

Heres a few shots of the frame mounts that Captainfab is speaking of. These are stock big block frame mounts from 1968-1971 Chevy and GMC trucks. They are a bolt in and move the engine forward enough so your not banging up the firewall. You will need to trim the upper edge of the frame back a little, they did this on the 68-71 frames also from the factory. You can see what I did in the close ups of the mount. You will also need to move your trans crossmember, I just bought one on-line aftermarket and redrilled the holes. Very easy swap, these mounts also give you more clearance for stock exhaust manifolds. I ran Sanderson headers here with no trimming or clearance issues.

60-66, I did a quick search for the motor mounts on line and I'm not coming up with much that looks like the ones in the photos. Ony ones I can find are on ebay for over 300.00. Where is the best place to find them? My local pick a parts have been pretty hit or miss on my past projects. Prior to buying/building the engine I want to try to fit the mounts to make sure I'm not biting off more than I can chew. Looks easy enough from the photos, but I'd hate to have a new engine sitting in the garage that I cant use!

[PLYONS11]

Thanks guys! Knowing that I can fit a BBC in the truck is getting me really excited to get started.

60-66, what did you use to trim the top of the frame rail? Will a cut off wheel do it? I also noticed it appears that you are converting to power steering but have not plumbed it yet??? Is that from a 70's truck? Did you have to modify the shaft at all?

I am going to get the truck later this month. I'll be sure to post some photos of the progress. I'm sure glad you guys and this site are around. I'm sure I'll be blowing up the site with new questions every day! My biggest concerns are just getting the right engine, trans, and rear end combo. This will not be a daily driver, but it will certainly be a weekend warrior. I want to be able to cruise at highway/interstate speeds with ease and comfort. I plan to make it somewhat of a "rusto-mod". Bad a** engine! nice interior, modern drive components, and original as it sits exterior.

[60-66]

Originally Posted by PLYONS11

Thanks guys! Knowing that I can fit a BBC in the truck is getting me really excited to get started.

60-66, what did you use to trim the top of the frame rail? Will a cut off wheel do it? I also noticed it appears that you are converting to power steering but have not plumbed it yet??? Is that from a 70's truck? Did you have to modify the shaft at all?

I am going to get the truck later this month. I'll be sure to post some photos of the progress. I'm sure glad you guys and this site are around. I'm sure I'll be blowing up the site with new questions every day! My biggest concerns are just getting the right engine, trans, and rear end combo. This will not be a daily driver, but it will certainly be a weekend warrior. I want to be able to cruise at highway/interstate speeds with ease and comfort. I plan to make it somewhat of a "rusto-mod". Bad a** engine! nice interior, modern drive components, and original as it sits exterior.

I used a sawzall then just cleaned it up with a grinder. As for the power steering, Captain Fab sells an Excellent PS adapter plate among other things that show step by step what to do. My truck is up and running as of last week. I used all 68-71 PS pump and brackets on a short water pump. Most of these parts are pricey on Ebay, but if your not in a hurry can be found very reasonable. The rubber mounts are now reproduced which brought that price down a bit. As 1963C-10 says long water pump is an option as brackets are much cheaper but I don't think it will work with the frame mounts, you also will have do ding in the firewall with the stock mounts from a 63-66 v8 truck. That's why I chose the 68-71s, gives you more room by the firewall for an HEI, valve covers etc, but there are plenty of opinions and directions that work fine. This is just mine. If you need more pictures, no problem. Jon

[1963c-10]

Im in the middle of the same conversion on two trucks. One is a 63 stepside getting a 427 and one is a 63 fleetside getting a 348 1st gen big block. One is an auto and one is a manual, so I have figured out a lot of the issues and this forum can answer most of the questions and concerns you have with the swap. I believe most are auto's, but if any questions on the manual swap, let me know. I also converted to a hydraulic clutch as CaptainFab mentioned. Was not a bad conversion if you choose to go that route.

Only difference in my build is the engine will be in the rear mounting location being a manual, and hydraulic clutch. Most guys also opt for a SWP system and I went LWP, but again I'm using the rear mounting locations.

[PLYONS11]

1963c-10, The truck is currently a manual, and I love driving a manual, but I'm considering an auto swap. My Mustang is a manual and my wife hates driving my Bronco (its too big or something???) and always complains that I have no cars she can drive. I figure since I am spending our savings to do this project, I would try to accommodate her. Is it necessary to use rear mount location if going manual? I would imagine that there may be some clearance issues with a LWP in the front mount position?

Sorry about multiple questions/issues on a single thread. As I am new to the site I’m not really sure how all this works. Feel free to verbally abuse me and correct me if I am doing something wrong!!!!!

[66LSx]

I'm partial....

LS swap...

Vortec truck engines belong in trucks...

So here I am.... 2005 Silverado 5.3L / 4L60e
EFI
MPG
easy starts
easy parts
cheap parts
easy to implement
expen$ive to implement (kinda.....)
cruise, tow/haul mode, turbo? all future items

better like wiring.

[1963c-10]

Originally Posted by PLYONS11

1963c-10, The truck is currently a manual, and I love driving a manual, but I'm considering an auto swap. My Mustang is a manual and my wife hates driving my Bronco (its too big or something???) and always complains that I have no cars she can drive. I figure since I am spending our savings to do this project, I would try to accommodate her. Is it necessary to use rear mount location if going manual? I would imagine that there may be some clearance issues with a LWP in the front mount position? I imagine that you could run a manual in the forward holes by going to an aftermarket or later model manual trans mount meant for the tailshaft style mount.

Sorry about multiple questions/issues on a single thread. As I am new to the site I’m not really sure how all this works. Feel free to verbally abuse me and correct me if I am doing something wrong!!!!!

I'm using the factory bellhousing crossmember, so I'm kinda limited to the rear mounts, which is the only reason I went LWP since its what I had available. I don't believe the LWP set up will work with the forward holes. I know I will have to massage the pass side fire wall some and I currently have a large Mallory HEI...that I will swap out for a small head HEI with external coil to allow more clearance.

[60-66]

These are the ones your looking for http://www.ebay.com/itm/NOS-67-71-Ch...e80fe2&vxp=mtr
but used ones I can find for 50-75.00 or less. Check the classifieds here under 67-72 trucks, might find something. I've never used the 1972 up mounts, maybe someone else ?

Early Classics sells the rubber mounts here http://www.earlyclassic.com/catalog.aspx and I'm sure there are other vendors and prices. The same 68-71 PS hoses work well, they reproduce most of the brackets now I see. Check local guys into 67-72s, its out there.

[Captainfab]

I prefer to use the '73 and up engine mounts. The frame brackets from the C20 and C30's fit the '63-'72 frames better than the C10 brackets. However I can not verify that these will position a big block far enough forward. It should be close to the same location as the '68-'71 BB mounts. The clearance to the firewall will also depend on the valve covers used. I always recommend using a short water pump and related accessories in these trucks, particularily with a big block.