I am putting the engine and trans(383, 4spd) in my '56 Chevy 150 right now and had a question about firewall clearance. I am setting the engine on the stock front mounts at the moment in order to locate and drill holes for my Speedway side mounts. This engine has Patriot heads which seam to be taller than stock at the valve cover mounting surface. I also have tall, baffled valve covers. It appears I am going to need to alter my firewall slightly for clearance on at least the left valve cover. How much clearance should I allow between the valve covers and the firewall? How much could the engine potentially move with these mounts?
You shouldn't have to make any modifications to fit a small block. I know a lot of guys will "loosen" the body bolts and move the body as far back as possible. There is so movement to be had.
Move the engine an inch forward. You can buy mounts that do this. Helps with distributor And value cover clearance. Short pump will work fine.
The body is already as far back as possible and I still need about 3/8"... or shorter valve covers(no dice as I've got roller rockers).
I am really hoping to keep the engine in the stock location. Also, aren't all the kits to move the engine forward a different style than my Speedway mounts? I have these http://www.speedwaymotors.com/Speedway-1955-57-Chevy-Car-V8-Motor-Mount-Kit,52296.html These appeared to me to be the nicest style with regard to potential removal/installation of the engine in the future.
I have a big block in my 55, when I did the swap 18 years ago, I bought some side mounts that set the engine forward 3/4" which sounds perfect for what you're doing.
When you start moving the body on the chassis, or using the 1 inch forward mounts, you start messing with the alignment of the clutch linkage, so it's probably better to keep the engine in the stock location. But, with BOTH aftermarket heads AND tall valve covers, you're probably on your own. When you say the "LEFT" side, do you mean driver or passenger side? Usually the passenger side has more issues with interference due to that head being farther "back" on both small and big block Chevrolet V-8's. It took a LOT of firewall massaging, especially on the passenger side, when I put a 375 HP 396 in my 150 Bus Coupe back in 73 using Hurst's front saddle mount; that was long before side or the moving the engine forward type side mounts. The other issue, you say 383, so are you using the 400 external dampener? Not much will be left of the stock mounts if you have to modify them for clearance. If your engine is now internally balanced, then those mounts should be fine, but even then, some modification may be needed. I am Butch/56sedandelivery.
3/4'is correct. I messed up. When I worked in a shop that did mostly tri fives we used the forward mount most of the time. It cleared the big GM HEI and the valve covers. Anyway you gotta change something to get it to fit.
I meant drivers side. The passenger side appears that it will just barely clear(1/8"?) when the engine is in the correct location.
I have no objection to massaging the firewall. But I do not know how much clearance I need to have when I am done.
DRIVERS SIDE IS ALWAYS LEFT. I sold parts at Ford dealer in the 70's. Parts mgr had a great saying when a customer wouldn't know: he would hold up his left arm & say "this is my left arm, right?. then turn around & say "it didnt become my right arm now, did it?
Great when the manager is a smartass! That'll keep those pesky customers away! Ha! Back in the 80's I ran a 327 with the (yuk) Moroso gold tall VCs and adjusted the solid lifters with no problem. Stock location mounts. Judicious hammer work to fit the BBC now and not move the whole works forward. Worth it to me, I'm interested in keeping weight to the rear. Moving weight forward is the wrong direction IMO.
You have some leeway with the Speedway mounts. Hang the engine and see how far forward you can move the frame brackets. 1/2" clearance between heads and firewall should be enough. At least with tri-fives the trans cross member can pretty much be put anywhere you need it.
The stock front mounts usually work the problem is the "stock" rear mounts on the bell-housing the always sag bringing the distributor and valve covers closer to the firewall put a transmission mount in on the tranny as long as you are not using a turbo 400 and you might find the clearance you need Pat
Tri 5's have very little clearance by the firewall and with the wiper motor installed it can present problems installing the distributor. I have seen guys modify the firewall to add more clearance. Not thinking about any of this at the time, I ended up putting my 56 Chevy SB engine in the stock location. If I had known, I probably would have moved it 1" forward for better distributor clearance. The distributor was tight (as you can see in one of my pictures) and did hit the firewall. My problem was solved by installing a mini HEI distributor which fits much better and works great. I also put my radiator in the 6 cyl position which allowed me sufficient mechanical fan and fan shroud clearance. If your battery is in the stock location and you run a tall valve cover, you may run into a clearance issue there.
Are you going to have room for your distributor ? I have a 55 with a 350 and my HEI is right against the firewall, luckily I have solid mounts.
I should be fine is this regard. I haven't gotten a chance to drop the new distributor in yet. But, it is a small cap Pertronix distributor, so I don't expect any trouble.
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