Hello all,

I am new to the boards and looking for some advice on an engine swap. I am interested in swaping out the tired old 6 in the '38 GMC for a new 292. I like the fact that its still a I6 and yet will give me great torque and power. Im just making a daily driver and will pull a small trailor, so not looking for tire roasting hp. Anyone have experiance with this swap? Tips/ pointers? Thanks for having me aboard.

Cornstalk

Are you planning to keep the stock trans and rear end?

As for transmission swap I have been thinking about either the NV3500, NV4500, or T-5. I guess which ever one I can find would be what I use, unless I hear pros/cons of one or the others. The rear end I have been told could come from a 2002 4wd blazer which has disc brakes and is the same width as the stock rear end. I will also replace the front brakes with a disc setup. I figure i will find more things as I go along, but Im young so it should be a great experiance. I am away from the truck for the next two months finishing my jr of college and heading to korea for awhile, but am trying to get things lined up so i can get right to work when I get home.

EASY SWAP TO 292 BUT FINDING A GOOD CORE TO REBUILD MIGHT BE A PROBLEM. ALSO UPDATE YOUR COMPLETE DRIVE LINE WHEN DOING THE SWAP. ALL YOU NEED IS A GOOD STOCK ENGINE FOR YOUR APP. I WENT THRU 3 292'S BEFORE I FOUND 1 WORTH REBUILDING AND EVEN THEN I HAD TO SLEEVE #1 HOLE, .060 WOULD NOT GET IT IN SPECS. FRONT CYLINDERS ON CHEVY 6'S WEAR "ALOT" COMAPRED TO REAR CYLS.

Thanks for the reply. Also, S10 T-5 (1983-89) will bolt right up correct? I believe from what I have read that this set up would provide dependable and easy driving at highway speeds (65ish). Then the brakes to stop it will be the big priority.

A T-5 WONT HOLD UP TO THE TORQUE OF A GOOD 292 IF YOUR GOING TO WORK IT..... IF IT WAS ME I,D INSTALL A TH350 TURBO

My '53 Pickup has a built 270 GMC a T-5 From an S10 and a Dana 44. I can not imagine a daily driver that takes more abuse than this old truck. The T-5 has held up well. On the other hand the 350 in my '68 flatbed turned two 350 turbos inside out on the same roads.

ALOT OF diifference in torque between a 270 and a 292. if your just ridin around it will be ok but the design of a t-5 isnt for the amount of torque a 292 makes, just look at the puney u-joints, that tells the story basically. a 292 normally has a sm465 behind it for a reason....

I think the max torque on a T5 is around 350ft lbs??.

I am sure there are different T5's w/different max torque specs.

T'5's have problems when you are running slicks, hooking up well.

If you just drive it normal, & am sure the T-5 will last a long time. Don't the Chevy/Ford V-8's make more torque than a 292?

I even used a couple whimpy T50 5 speeds that came in Chevy Monza 4 cylinder cars in my 250 4 bbl ,headers etc engine.

First gear was like 4.0 & I had 4:10's in the rear, I could not even get through an intersection in 1st, I would have to shift into 2nd gear in the middle of an intersection, crazy low 1st gear & OD was like .98 in 5th gear. Not the best gear ratios for my combo by any means, but I got them for $75.00 & they both worked good until I was ready to install my 4 speed.

They worked fine until I tried to speed shift them & bang the gears hard, then 2nd gear would give out quickly.


MBHD

DONT THINK ITS THAT HI AS A CHEVY V-6 IN S-10 WAS A GUTLESS ENGINE COMPARED TO A 292 MUCH LESS THE 4 CYL THEY CAME BEHIND.

T5s were used in many V-8 applications A.F.A.I.K.

MBHD

There can not be a lot of difference in the torque of a stock 292 and a .040 over 270 with a 3/4 cam, .030 shaved head with 1.86 and 1.6 valves and a 4bbl carb. Especially when it come to transferring that torque to a steep rocky road that climbs 2000 feet in two miles.Then theres the down hill run.

THERES ALOT OF DIFFERENCE THE LONG ROD MAKES IT A TORQUE MONSTER AND SEEINGS HOW LOW YOUR OLD PICKUP IS YOU CANT HAUL MUCH WEIGHT.
I,AM DONE AND SAID MY PIECE SO RUN YOUR T-5'S

THE LONG ROD MAKES IT A TORQUE MONSTER

How does it do that?

I have read short rod motors make more lower end torque.

Longer stroke engines makes more torque no?

MBHD

GEE WONDER WHY ALL LONG STROKE ENGINES OUT PULL SHORT STROKE ENG. ALSO WONDER WHY GM NEVER PUT A 250 IN A 1 1/2 TON AND UP H/D TRUCK ?

Running a short rod motor creates alot a lot of cylinder wall stress on one side, = not good.

I was just going off of memory when a mag compared a 383 SBC engine & running the 400 5.560" rod to a 6" rod 383 engine, IIRC, the short rod engine made a bit more torque down low in the RPM range, I could be incorrect, just going from memory.
Cant believe all magizine articles, but my friend that builds mostly SBC' for a living, had dynoed tested long & short roded 383's & 400's with the same type of results.
Now he mostly builds LS engines.

The one reason the 292 has such a long rod in to is so the rod to stroke ratio wont be that bad.
The 292 engine needs to run a long rod to clear the counterweights of the crankshaft , no?


The stroke of the crank is what is giving it more torque,(longer arm = more torque) not because of a long rod.

I have heard a lot of people think that the 302 SBC have the best rod to stroke ratio.

MBHD

It's not the rod,It is the Long stroke of the crank. EXample a 292 crank in a 250 block Is still a 292 motor It's just now a Low deck 292 and Not a Tall deck.

The truck is that low because in one picture it is loaded with 3/4 cord of almond firewood. It hauled 8 of those loads that year. The engine in the other photo is a 413 ci Dodge flathead six. It weighs over a ton. The 270 and 292 both have 4" strokes. Here are some rods to compare. Left: GMC 228-302 Center: 292 Right: Ford Flathead The longest one is the Ford Flathead V8.

Chevy big trucks ran 216s for years. The big engine was a 235.

Nope, I'm not going to go through all this again other than to suggest that "torque monster" as a claim has had zero basis 99% of the time I've examined them.

WHAt about the tall deck 427 "only in h/d trucks" .400 long rod eng.

What about the tall deck BBC's did the tall deck make more torque or more power than a standard deck 427?

Lets see some numbers.

I always thought those were low performance engines as compared to the standard deck BBC's.

MBHD

TORQUE DOES THE WORK AND GM ENGINEERS WOULD NOT HAVE MADE/INSTALLED THEM IN THE H/D LINE OF TRUCKS IF THEY DID NOT DO AS DESIGNED ALSO ALL H/P RACE ENGINES GO FOR LONG RODS AS POSSIBLE FROM THE HEMI ON DOWN. NOW IF ALL YOU WANT TO DO IS REV THEN A SHORT ROD COMBO "MIGHT" BE REPFERED. THIS IS MY OPINION AND YOU HAVE YOURS SO WE'LL AGREE TO DISSAGREE OK ?

All BBC engines,including the tall decks used a rod that is 6.135" in length. The difference in the deck height in the tall decks was made up for with a piston that has a .400 taller compression height and had 4 piston rings instead of 3 that the passenger car engines have. Hank is correct, these engines were low performance and low HP.

Still wondering, what was the output of a tall deck long rod 427 BBC as compared to a standard deck 427 BBC?

I do not know the answer, I would think you do?

Just some quick reading, the tall decks were heavier, could normally bore .100" over = thick bores.

CNCdude says there are 4 rings, that was probably so they could seal better for a longer period of time (more miles)? just a guess, but adding more rings causes more friction & will therefore make less power, unless GM used low tension rings?

So the rod is not longer in a tall deck BBC, just the comression height is changed by using a heavier piston?

Wasn't there a 366 tall deck truck only BBC also, another low performance engine?

I think long rod engines overall run a bit better.

When ever I build my new 250 engine it will have just a 6" rod.

MBHD

Yeah, they made a 366 tall deck also. Never could find any HP/torque specs on the tall deck engines, but there was no long rod version ever made by GM. BC may be thinking of when you use a tall deck 427 block to build a race or performance 427 cubic inch engine you have to use a .400 longer rod to use the passenger car 427 style pistons or you end up with a piston that weighs 5 lbs because it has a 2.140" compression height.

Here is a stock 427 tall deck truck piston with the 4 rings, it also has a steel ring land insert in it.

Hey all,

I appreciate the repsonse to the thread but I must say that I do not expect to make a tire burner out of this truck. I have 35 days to turn this truck around and make a 1000 mile road trip from IN to NH. Im young (and dumb) but have the advice and mechanical ability of a few older gentelmen that will be able to help me in this project. I just wanted some outside advice so I can start lining parts up before I get home to start on it. I know, 35 days is a short time, and old trucks need lots of attention. But who said young guys like me don't already know everything. So 292 can be dropped in with out much trouble, I just need to find a good running one. I would drop in a small block chevy but then that leads to more changes like steering box and radiator moved forward correct?

I RUN 6.800 RODS & 5/8 STROKE CRANKS IN ALL MY T/D DRAG BBC ENGINES AND 6.535 W/454 PISTONS IN MY T/D H/D WORK TRUCK ENGINES AND THEY EAT THESE MOUNTAINS HERE IN E.TN UP & VERY DEPENDABLE