47-55.1 V8 Swap

[studeclunker]

I can relate, this is basically what I am doing with my '58 Apache 38. Only my focus is the truck still remaining a workhorse. Not speed, per se, but power. However, I would like to be able to keep up with traffic as my current, pedal-to-the-metal, top speed is a blinding 50 MPH.

[mr48chev]

I'm just going to say take a long look at Gray Beards mounts and figure out how to fab your own or (as much as I hate to use the S word) Speedway sells a
set that can be trimmed to fit or the image can start the "Hey I can fab those with that stuff in the _____ ' process.

[nvrdone]

here's another idea for the trans mount. After I got my engine mounts figured out and drive line angle set, I bolted the trans mount to the bottom of the trans. Then I used some 3/16" plate to mount to the frame rail and hang down to the trans cross member. then bolted the plates to the frame and crossmember. That has worked well for many years and gives enough clearance for my under cab brake booster. It's a bit low but so far no scraping on the pavement

[dsraven]

check out welders series for all kinds of misc brackets, urethane goodies, tubing, threaded joints etc. they are Canadian so the USD goes further and they ship quickly.
still, nothing wrong with using a stock mount bolted to the engine and then build a connector from there to the frame. make it unbolt from the frame to really quickly open up an area for getting the engine and trans in and out as a unit without hanging up on stuff. for the trans mount, get the engine where you want it and the truck sitting on stands at the same angle it would be if it was sitting on the ground. then install the trans mount you have picked out and bolt a plate up to that which will be your new plate attached to the new cross member. then design a cross member that will attach to the frame and also fit up to the plate mentioned above. square tube works pretty well but round DOM tubing works pretty well and can be bent by the local muffler shop likely. keep in mind that there will also be exhaust to run past the whole system there and also possibly a brake booster if you go witn a frame mounted booster some day. even that though, can be mounted wherever you decide and then it just becomes a linkage issue with how you make it work.
you got this man.

[dsraven]

if you want a stiffly mounted engine that will possibly make everything in the truck vibrate then go with a pretty solid mount. if you want a pretty vibration free experience then go with more of a stock engine mount and build frame mounts to connect the dots from the engine mounts to the frame.

[dsraven]

one other thing to consider, and don't get me wrong here I am not trying to call anybody else's stuff down, is that without a cross member where the old stock trans cross member was, the engine becomes the link from one side rail to the other in a build like greybeard's that has no original trans cross member but instead has a new cross member quite a way back on the frame. this can be hard on engine mounts as they take the normal engine mount load as well as some frame flex load because the frame is less stiff in that area. it can also be hard on the cab because the frame flexes with the load of the cab mounted on a "lever" on the outside of the frame rail, which naturally wants to twist the frame. possibly greybeards frame is not a current pic or one before the finished product or maybe there have not been problems with his system. just theorizing here so you van get it right and have no issues later.

[dsraven]

here is an example of the welders series motor mount
https://welderseries.com/store/Rubbe...v-PR-p51163355

[dsraven]

and an example of the clamshell style that bolts to the engine and you fab the frame connector to fit up to it. possibly less vibration from this unit with a stock type motor mount inside the clamshell.
https://www.hawksmotorsports.com/gm-...dually-hooker/

[dsraven]

or this stock replacement part. hey, they worked for GM pretty well. why not?
https://www.speedparts.com.au/~975041

[mr48chev]

The what you called a clamshell was a safety thing as it kept the engine from rising off a broken motor mount. Some of us older guys did experience a broken motor mount that let the left side of the engine lift and cause the throttle rods to stick wide open. That called for a fast reach for the key to shut it off. I had that happen on the first 62 Impala I had in the early 70's.

[dsraven]

yep, played havoc with wiring, headers, shifters etc. I had a guy who said he had 2 problems he wanted fixed. one was a clunk when he shifted or hit the gas etc. the other was the trans slipped out of gear when he hit the gas hard. the motor mounts were toast,

[dsraven]

the nice thing about the tubular urethane bushing style mounts is that unless a mount breaks off the frame or engine or a bolt breaks in the mount, the system will keep the engine roughly in place even if the urethane disintegrates. they are relatively compact too so if working in a tight space with steering shafts and exhaust to fit in the area too they can be a good choice. they don't really have a lot of vibration absorption though, in my opinion. some will likely disagree but thats fine.

[studeclunker]

Originally Posted by mr48chev

The what you called a clamshell was a safety thing as it kept the engine from rising off a broken motor mount. Some of us older guys did experience a broken motor mount that let the left side of the engine lift and cause the throttle rods to stick wide open. That called for a fast reach for the key to shut it off. I had that happen on the first 62 Impala I had in the early 70's.

Many brands had that problem. With Studebakers, the engine mount would break and slam the engine against the firewall, thereby breaking the Distributor cap and Rotor. I fixed that problem by using the rubber engine mounts from a Land Rover.

[Grey beard]

A lot of good comments posted regarding the engine/transmission mount designs. The mounting system I built for my 54 was patterned off what I built for my 36 Chevy pickup which has 80,000 + miles on it now and other than one LH rubber motor mount that delaminated I haven't had any other problem. The urethane mounts fixed problem. I had a 66 Chevy II with a 327 4 speed that destroyed the LH motor mount until GM came out with a steel cable that went from the frame to the LH exhaust manifold to limit the engine roll. My transmission crossmember end plates are made of T1 steel angle with the 1 ½” .250 wall tubing welded to both the vertical and horizontal parts of the end plates and bolted to the frame side member and the lower flange. I’m not able measure how far it is behind front cab mount currently, but here’s a couple of pictures. The 36 cab mounts are bolted through the frame flange and the 54 mount brackets extend away from the frame but the 54 floor structure is much stronger than the 36.

[Grey beard]

Opps no pictures hope this works !!

[dsraven]

greybeard, I like how you built that with the removeable centre section or the whole thing could be unbolted good thinking since it is impossible to get a cross member out that is bolted to the upright section of the frame.

[Jemezcrusher]

I think I have a task force bell housing sourced. Here is a pic of the engine compartment with my 235 in place. Should be easy to modify the steering shaft if needed. I assume virtually all sbc engines will bolt up to the task force housing? Does it rest in the same spot as the older housing that also provides support between the frame rails? Please note the fancy hoses for the added spin on oil filter set up.. Including a little eye candy of the 55 I referenced the other day

[Jemezcrusher]

Wrong truck pic

Here is the engine area, drivers side

[Jemezcrusher]

I think that is the way I will go. Got my builder 350, standard bell housing, rear dump truck exhaust manifolds, and all the brackets and accessories

I'll build rubber mount type side mounts and then a rear. Seems easy since the motor stuff fell in my lap

[dsraven]

I suggest to remove the old engine and test fit the bell housing on the cross member first, just to see how it fits. use some new rubber mounts. then you can decide to either bolt it up and then lower the engine in to fit up against that or remove the bell housing from the cross member and bolt it up to the engine and lower the whole thing into place as a unit. I suggest to also place the new engine into the space without exhaust manifolds attached for ease of access and then set the engine and bellhousing on the rear cross member at the rear and a stck of 2x4 blocking at the front so you can safely bolt the bell housing down and also see what you have for room to allow side mounts and exhaust in the same area but also allow the steering shaft room. if you could borrow a set of manifolds from somebody for test fitting that would possibly save some cash in case they don't fit. I have seen some hooker branded manifolds that hug the block a little better but that may make the engine mounts a little tight for access. you could always do front mounts though

[dsraven]

sorry, I thought you meant you have a v8 style bellhousing with the cross member mounts. then I responded and hit post, then I read back through your last post and seen you said you got a standard bellhousing, meaning it doesn't have the cross member mounts likely?
if you get a minute post up some pics of what you have.

[dsraven]

nice clean underhood area, shows well. great job.

[Jemezcrusher]

I think I would lean towards the rubber mounts. I have urethane mounts in my 55 sedan and urethane body bushings and feel most of everything. Even thinking about changing out the body bushings back to rubber

[dsraven]

yeah, they are durable but not that flexible compared to stock rubber. thats why the guys use them in suspension points, because they stay more true to a centerline axis than the rubber. I like a tight suspension but there is a limit. on my current build I am usimng the stock rubber body mounts. i don't like dental work. haha

[Jemezcrusher]

dsraven, I ended up with the correct bellhousing that bolts to the original crossmember. I am assuming my Heidts front crossmember for the rack and pinion is different than the original I took out. Am contemplating the old front mounts from 50's V8s assuming that while possibly needing some modifications, would give me plenty of room for exhaust options