I have a bunch of cars and have been selling some off. I'd like to get down to maybe one hot rod and it will be this recently acquired '48 Chevy Sedan Delivery. The reason this one is a keeper is because I like to do road trips and this is well suited for that. Lot's of room inside, rides nice, and I can tow a custom teardrop trailer behind it. It's a 350/350 combo now with a 3.55 or 3.73 gear. The engine seems to be stock so I'd like to do a cam, intake, carb swap and maybe heads to get a little more power and nice loppy idle. I'd also like an overdrive trans so I can drive 65 to 70 MPH a little more comfortably. Many have suggested the dreaded two letter modern engine and trans swap but I want to keep it more traditional old school. Thinking about going with 3 deuce carb set up or even dual quads just for the look. Then I saw this Mopar with a 392 Hemi in it and thought that is pretty cool. The sedan delivery is not a common car to begin with and having one with a 392 in it would I think, be really neat. Now 392 Hemi's are not easy to come by but I just happen to have one! I bought this a few years ago to put in a '34 Ford coupe I had but it was a glass car and I just thought it deserved to be in a steel car. I sold the '34 and figured I'd probably sell this engine too but now I'm rethinking it. It's a rebuilt '57 factory dual quad from a New Yorker. I'd want to paint it a different color (maybe red), dress it up a bit with some nice Hot Heads stuff (polished intake, valve covers, air cleaner, etc.) before I put it in. There is plenty of room under the hood for it so I don't think that would be an issue. Not sure what trans to go with but it would have to have overdrive. Hot Heads makes adapters for different manufacturers so I could with a 700R4 or something like that. I don't know if there is a Mopar overdrive trans that would bolt up. Or I could go with a 727 and a Gear Vendors although that's a more expensive route. My only hesitancy about doing this is gas mileage. While I'm not too concerned about the cost of gas but more so, would be fuel range. The car has about a 12 gallon tank which is pretty small. I intend to replace it with a larger one and will carry extra fuel cans when I travel. I live in NV and all through the west there are long stretches of roads without much in between. It would be nice to have at least a 300 mile fuel range. Do you think this engine with an overdrive trans can get at least 10 MPG cruising at 65 to 70 MPH? That would require a 30 gallon gas tank which is pretty large. I'd be really happy if I could get at least 15 MPG at those speeds. maybe with overdrive and a bit higher gear like a 3.08 would be the solution. I'm not drag racing it and with the extra power of the Hemi and a 3.08, it would still perform nicely.
Should I Hemi swap? That is the question. It’s a no brainer if you don’t do it you’ll be kicking yourself later for not doing it .
"A hemi swap lowered my cars value" said no man ever! The only problem I see is with a SBC you keep the hood closed, with a Hemi? You may be leaving it propped at shows.
Match the gearing, cam, and induction, and you should be able to get 13-15 mpg out of it. Hint: think "stock" or "very mild" But it'll be a huge can of worms to get it all together and working well. I hope you're up to it.
No doubt a killer with the hemi. The Chrysler’s those came in would roll across the country in style and at speed. Not sure about a 300 mile range. You say road trips and long lonely open roads. From where you are, most directions are a serious mountain pass sooner rather than later. Full load in the delivery, and a small trailer behind. I’d be more inclined to drop a crank in the 350 for 383 and build a moderate motor with good low and mid torque. Bolt up a 700R4, or a 20004R (you use might like the low first in the 700 better). Then live with a single quad. A Quadrajet, or something with at least good primary performance. Be easier to deal with on the road, better mileage, cooling, and long haul drive ability. Not as sexy with the hood up, but much easier to drive all day and maintain. And a big auxiliary tank.
Oh Hell Yes - that the standard answer if anyone asks if you need a Hemi in your car. Thats just how the world rotates. and its not like you can fight the world's rotation. But in your case, I think you need to keep a second car from your collection for the Hemi, or go find a Model A RPU and fit the Hemi to that, and leave the Chev with its SBC. You could add a 671 to the 350 and then you wont be shamed by opening the hood, and knowing you have a Hemi at home will do wonders to keep sadness away.
Now, there you go being all sensible and shit. This is probably the best way to go and was my original plan with the car. Wasn't really thinking stroker but rather keeping it a 350 and going with an RV type cam for the low and mid range torque. I live at close to 5000 feet elevation and yeah, lots of mountain ranges to cross from here. Engine cooling would be a concern too climbing long grades under load and 100 + degree air temps. The car is a running good driving car now so the Hemi swap would require it to be down for probably longer than I want. Those kinds of projects always take longer and cost more than you expect. A cam, intake, carb swap of the SBC could be a weekend job.
If you keep the 350 in it, you might consider how your proposed changes will affect the car in the opposite way from your intended usage. For mileage, you really want to keep the stock cam and gear it for appropriate rpm. That means the 3.55 gears (or even longer) and OD, and a stock intake and Qjet work really well. I went through this with a few different rides, my 57 Suburban ended up getting well over 15 on the highway with stock 87 350 converted to carb, 3.0 gears, and OD. And it was peppy enough for me. I also killed the mileage on my 62 Corvette by swapping heads/cam/intake/carb, went from 18 to 12 on the road. And adding all the higher RPM stuff isn't really going to help towing, you need low-midrange torque for that, and that is what stock engines are designed to make. If you were planning to go racing, then you want to run the engine at high rpm. I don't think that's what you have in mind.
I had also thought about leaving the SBC and doing my road trips for a couple years and then doing the Hemi swap. I think your idea is better though. Instead of trying to have one car that does it all, better to have a couple that kind of have different purposes.
I'd measure twice, or maybe three times...the engine compartment was built to accommodate a straight six, a Hemi takes up a lot more space.
I agree with your thinking on this. The engine is all stock and even has a 2 barrel carb on it. The hot rodder in me wants to modify it but I think for what I want to do with the car, I should leave the engine alone and concentrate on the trans, gas tank, and other things that will make it a better touring and towing car. Thanks for talking me off the ledge. Oh, and along the lines of building a long distance hauler, I want to raise it up an inch or two. It looks cool now but not practical when I want to pull off the pavement.
I'm surprised that no one has mentioned the ~200 lbs increase on the front suspension the hemi would add vs. the SBC. You didn't say what the present suspension is but I'll bet you'd have to do some beefing up to deal with it.
I didn't mention the front suspension because it is OT (Camaro clip). This is something I considered as well. I plan on changing the front springs anyway because it sits too low for me right now but I'm going to leave the SBC in it.
The responsible thing to do is do as @squirrel has said but you can’t beat the cool factor of a Hemi!
I just finished a 3200 mile trip in my '47. 350 / 350 with 3:00 gears. Cruises all day at 75 getting 20 mpg with the air on. I think.that's a pretty good reason to stick with what you've got. Put your hemi in a hot rod. Just my opinion.
My current formula for building a powerful but reliable with decent mileage is cubic inches with low to medium compression. For that reason plus the fact that I had a Cad powered 33 Ford in the sixties, I'm going to use a 500 Cad with a Tremec 6 speed. I won't go into details, but I expect 500+/- Hp and maybe 600 lbs/ft of torque and it only weighs about 50 lbs more than a SBC. I will be able to use regular gas if I don't put a blower on it. Now I'm not suggesting the Cad engine for your car, but the formula. I'd look into an aftermarket Chevy block with a 427 cu in displacement. Put your compression ratio about 10/1 and the cam of your choice. I'd run roller lifters and some aftermarket aluminum heads to take advantage of the displacement. You also get to keep from putting an additional 200 lbs on the suspension and probably a lot of cutting and welding. Yes the Hemi would look good but its a lot of down time and expense plus trans adapting. The 427 Chevy can produce at least 450 hp and probably a lot more while remaining tame and possibly getting decent mileage with the overdrive. Not paying that extra dollar for every gallon of premium also makes driving long distances more palatable. Just saying that instead of playing with cam duration, substitute displacement for a more satisfying result. For the overdrive, look for someone parting out an 88-92 Vette as a good source for a 700R4.
Did it 30(?) years ago as a prank. Notice valve covers laying on header pipes. Tin Chevy valve covers and plug wires there, too, underneath.
What other cars do you have to put the hemi in? I am not convince you will get the full bang for your buck putting it in the delivery. If the aim is lots of trouble free, fairly fuel efficient miles, I expect you have the correct drivetrain at present, if it ain’t broke, why fix it. If you break down who is going to fix that hemi for you out on the road. I respectfully submit that the hemi deserves some open hood hot rod that wows em close to home.
Ohhhh, an ultra rare hemi headed SBC complete with PVC injectors! I really like you flower pot holder though.
You are correct. I think what I have now other than lack of overdrive, is best for what I want. All my other cars are OT 1960s/'70s muscle cars and a couple Corvettes. Nothing suitable for the hemi. I've realized I have too many cars and am spreading myself too thin, time and money wise so selling them all. I want to get this car dialed in 100% to my liking and for what I want to use it for. Once it is done I can think about picking up something more suitable for the hemi. Ideally, that would be a '33/'34 or Deuce coupe but I think they are price prohibitive at this time. A Model A coupe or Tudor is more realistic. I wouldn't mind building a copy of this '29 I used to have but with the hemi and a stick shift.
The power level and the fuel mileage you want shouldn't be too hard to accomplish, right up until you want to hang on the custom teardrop trailer and want to drag it through the mountains. That teardrop could change the entire plan, since we don't know how easy it pulls. If you feel your current sbc is slightly under powered with the 3:55 gears, you won't like it at all with an OD trans behind it. Then you want to swap in 308 gears instead of the 3:55, with the OD? Its going to turn into an under powered, slow poke, real fast, climbing those mountain grades. That 10 mpg may become a fairy tail. Then add the effects of the teardrop following along up those mountain grades. The reality is, that OD trans probably won't be in OD most of the time you are in the mountains. That 10 mpg may be a fairy tail until you get through the mountains. More cubic inches (or torque) will be able to pull those mountain grades much better, will deal with the OD better, and will likely be less effected by the trailer in the mountains. With a properly tuned big block, you may get much better mpg with the OD then the sbc will get. The old school multiple carbs, intakes, and rumpity cams won't get you the road car it sounds like you want. Just my opinion.
For the cost of the hemi trans adapter to get a good modern trans on it you can replace the cam and intake and some other stuff on the existing SBC. The Hemi has a big cool factor the question is do you want to deal with it in a long distant driver? If its rebuilt and all good then it should be reliable but if it breaks on the road parts are slim and none . lot of extra weight with the hemi. Id want it more for a car were the engine is seen visibly. I have a 331 I'm going to put into something likely a channeled 31. HP increases fuel mileage. Doesn't matter if it's a 350 hp Chevy or a 392 Chrysler if the compression is about the same the gas mileage will be similar. You need a bigger tank either way.
Meh. With a Camaro subframe the Camaro engine and tranny are right at home. Leave it and drive the hell out of it. Maybe put houndstooth upholstery in it?
For 7 years I drove a '48 Plym with a 331 Hemi, 11 gallon gas tank & no gas gauge.....The NYer wouldn't have had dual quad....
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