The Stovebolt Site Forums The Shop Area The HiPo Shop Original inner fenders with small block?

I'm going to be installing a small block in my '42 GMC soon. I'm hoping to keep the inner fenders, anyone know if there will be room?

I'm right in the middle of fitting a small block into a 39 2dr. car.I have a 46 truck sitting beside it .Looks like engine compartments are similar in size.The only cutting on the inner fenders so far is fit over the MustangII upper control arms.I went to a pick a part and got the serpentine brackets and alternater,power steering pump,waterpump, and air cond. compresser,and fan,off of an 1988 GM pickup.1988 uses a steel braket instead of aluminum, and may be a little more compact.My engine is out of a 86 Impala and the alt, air comp. brakets made them stick out to wide on the drivers side, and I would have had to cut a hole in the inner fender. This serpentine set up is a lot narrower, and gives lots of clearance. I am also going to be able to run the 88 pickup fan by squeezing the rad ahead a little bit. I am using rams horns exhaust manifolds, and did have to grind a bit of the flange on bottom edge of the frame to make sure there was enough clearance. Hope this helps Jim.

You will need the inner fender panels to make mounting your fender easier. As Jcarter said you will have no problem with clearance with the engine but you will need to cut out for an IFS if you use one. I had to notch out for my pacer IFS but also had to make a circular bump out on the inner fender wall to give clearance on the power steering pump. I bumped it so I wouldn't have to worry...I didn't like the fender wall being about 1/2" from the pump.

Others who have put a chevy small block should be able to help more with the engine clearance. I went non-chevy and am sure very few have done the same.

jcarter, you mention grinding "a bit of the flange on bottom edge of the frame to make sure there was enough clearance."

I just repaired the frame on a 66 Chevy truck that had the frame notched to fit headers, only removing about 1/3 of the flange in a few places.
The left frame rail frame was cracked just behind the front suspension cross member and lacked about 1" of being broken in two pieces. The truck was driven to the inspection station where it was rejected....
I would be very careful when removing the flange of a frame. Be sure what you remove leaves a big smooth radius to reduce stress points.
Keep an eye on it for cracks.

Grigg

Same with my 46, all I had to do was notch out the area around the upper A arm on the IFS. small block V8s should not interfere. If your installing headers than there are headers on the market that mount closer to the block.Good luck.
Bob T

Grigg; Thanks for the concern about notching my car frame.I only removed a 1/4" and did radius it.Also on the car, it is a boxed frame with a flange on bottom of both sides of the rail where the bottom plate is attached to the formed rail.It was just a bit of this flange that I removed.I will be watcing it for any concerns when I get this on the road. Thanks Jim.

You may want to consider gusseting the frame where you have notched it. A little bit of extra "meat" can prevent problems down the road!

Sounds like it was done right J C

I think all of us are so truck oriented that we think we don't know the car frame on jcarter's 39 car is completely different. Our truck frames are open "C" channel while the car has a frame that is an a flanged channel that was open on the bottom that GM added a boxing plate to. Much more forgiving to notching as long as it's reboxed. The inner fenders will accept a small block without cutting if the straight axle is retained.

Yeah, I'm not really planning on installing IFS, I like the old straight axle.
I'll replace the kingpins, rebuild the front end and Upgrade to hydraulic shocks. I bought the motor mount and trans mount kit from Jim Carter. I'm going to box the frame, despite the fact that I'll be running a mostly stock 350 and it's probably not really nessecary, but you never know what may change with the truck in the future.
I almost feel bad replacing the 6 cylynder. I'm not sure what kind of condition it's in, since I havn't taken the time to do a compression check.
The crankcase was full of water after the truck sat out in the open for 9 years , rain ran right through the hood hinge and into the louvers on the top of the valve cover. I was, however, able to start it(after draining the water and refilling with oil.)The water pump is locked up and laying in the seat so I only let it run for a second, but thats not why I'm changing the engine out any way, I just like small blocks.

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mmcdaniel69- in the placing of the small block into your truck-did you have to move the cab?

I havn't actually installed the small block yet, but I'm very sure that you don't have to relocate the cab.
I had a friend with a 46, he built his own mounts and the cab stayed in place.
The only thing That has to be modified is the firewall. It has to be clearenced for the distributor, if your using the big HEI(which I will, because it's a much better distributor.)
The Motor mount/Trans mount kit from Jim Carter is a great value. It comes with the measurements and a diagram. I highly recommend it. Good luck, and if I run into anything that may help I'll let you know. Mike.

Oh yeah the inner fenders on the 46 had been removed, Thats why I wasn't sure.

If you don't want to massage the firewall you can use the Pertronix electronic conversion in you old point distributer and gain some room. I have that setup in my old forklift, 37 Buick, and 55 Chevy and all have been trouble free. Nice to be without points, condenser, ballast resistor,etc.

Thanks coilover
I already have the HEI, but I may pick up a points type distributor and convert it. I'll check the clearence. That may be an easy alternative.