The Stovebolt Site Forums The Shop Area The HiPo Shop What would you do with a 49 GMC Suburban?

I just bought a 49 GMC Burb and am new to the whole world of AD trucks.

These are my desires and I'd love some advice on how to get there:

A truck that is drivable: good brakes, good hadling, enough power, comfortable seats.

I know I want front disks, do I want rear too?

I think I want it lowered a bit.

I'm pretty sure I want a straight six. Should I look for a 270 or 302 or go with something easy to find like a 235?

A manual tranny is fine with me. Which one would you use with the straight six from above?

Thanks in advance.

Mike

Hi Mike, welcome to the Stovebolt!

I have a '55 1st GMC Suburban.

Mine has a 270 with the original type 4-speed, disk brakes on the stock front axle and a later rear axle with 3.08 gears on the rear. It isn't lowered except I'm running lower profile tires on 15 inch wheels. I have power leather bucket seats from a Honda Accord.

Its very drivable, stops great, handles like a SUV, will run the freeway at 70+, and accelerates well enough to stay with traffic, and the seating is comfortable.

Those are somewhat subjective measures, and you might want to change some of my choices.

I'd like power steering when I'm in a parking lot, otherwise it would not change driving this truck at all.

I've considered swapping the original granny gear 4-speed for a Saginaw 4-speed, or alternatively changing both the transmission and the rear axle to use a T-5 with overdrive.

While sometimes its hard not to trip over 235's, finding a 270 is not hard. Finding a 302 is a little more challenging, but they are out there.

If you are serious about running a GMC inline you should check out the forums at OldGMCTrucks.com. You'll find more information about these motors and possibly even find one for sale.

Thanks!

I'll be away from the internet until Monday morning. I'm looking forward to checking in then and seeing what else you folks have to offer.

My handle here is Millersburg49, since I live in Millersburg, Oregon. However, after I signed up, I realized a perfect opportunity that I passed up: Millersburb.

Oops.

Not to mention that my last name is also Miller. What a mistake!

Hi Mike; Welcome to the shop! Sounds like a good find.
Did it come without an engine? If it were mine, I'd keep it all GMC and rebuild what's in there now or look for a 270 or 302.

Keep it GMC. I have a '54 with the stock 248, 4 speed and rear end. I put discs on the front. It will run 65 easily with stock gears.

I would sell it cheap to this really nice guy I know who goes by the name "iceburgh"

Keep it original if you can. If you can't, the 270/302 route would be the least objectionable. There were several 4wd upfits available in the late 1940s and 1950s. I might try finding a Napco Axle and transfer case and making that burb snow worthy.

No, it did not come with any drivetrain. It has a rear axle, but it isn't stock. In fact, it's too wide.

I like the idea of putting an old striaght six in it. My favorite vehicles I've ever owned have had straight sixes: two Toyota Landcruisers and 280z.

Are there any years to look for or avoid when it comes to the 270 or 302? What do you know of aftermarket support for such engines?

Thanks again.

The later 270 and 302(1955 to the end) usesed a funky engine mount that bolted to the front at the sides. You can still use these motors, but you have to change out the front timing plate with an earlier chevy or gmc motor for it to bolt into your chasis. The Military 302s would need some machine work, but nothing that couldn't be done.

On the later 270 and 302 motors, they used a 6 bolt flywheel. It could be chalanging to find a 6 bolt flywheel that is set up for 6 volts. If you are converting the burb to 12 volts, this isn't a problem.

The 270 in mine is a '58 or '59 based on the casting number. Its been some years since I looked at that. And mine is 12-volt.

Aftermarket support for the GMC inlines is out there, but its not as strong as for the Chevy inlines and nothing like what you see for the small block Chevy or Ford motors.

The decision to go GMC inline will mean spending more money and making less power than choosing to go 350 Chevy. You need to know that and be comfortable with it before you start. I'm building a '54 GMC 1-ton and decided to go V-8 because I wanted more power. I chose a Cadillac 500 so I'm still dealing with limited and expensive after-market support.

There is an ATHS show in late August every year just a few miles north of you at Brooks. I missed last year but the year before I saw a couple of GMC motors for sale in the swap meet portion.

James Larrowe lives in Sandy (east of Portland) and deals in GMC parts and likely has a motor or two available. He is likely to have used performance parts available too.

If you are going to build a GMC motor you will want to join the forum at OldGMCTrucks.com. You'll find a number of guys there who have built 270 and 302 GMCs for 'high performance' street use. Mine is just a stocker.

i would put a chevy 292 6 in it 5speed open drive rear end and a front diec brake kit