The Stovebolt Site Forums The Shop Area Engine Shop Engine swap question

I have a 49' 3100 that had a bad front mounted 235 in it. I want to keep an inline motor in it. I have found a good running inline from a 74 nova which includes a 2 speed trans that is in really good working order. I'm pretty sure it's a 250. Anybody else used this motor for this truck. Looks like If I change the motor and trans mounts and it should work. I have just finished installing a TCI Mustang front end on it, and it's getting close to motor time. I really wanted to rebuild the 235 I have, but being short on cash, it didn't make sense. There seems to be a lot of great inline's that people are selling for cheap.

should go in fine. you will need a new bellhousing for your tranny. 235's use an old pattern, and the 250 has the modern bolt pattern (same as a sbc 350) that will mate up to any modern gm tranny (like a th350, th400)

Thanks! I guess I could use the bell housing I have from the 235 motor I have, but if I get this motor I think I would keep the 2 speed powerglide. I am going to put a camaro rear end on it, should I ditch the powerglide and go with a th350? Will the th350 bolt right onto the nova 250? I was planning on keeping the powerglide to keep it cheap.

IMHO I would go ahead and use the PG. I see little gain in using a 3 speed tranny such as a TH 350. Why not use the Nova rearend too?

The advantage of the THM350 is the extra gear. It really helps with acceleration...ever converted a PG car to a turbo 350? It's like you added 100hp. Plus the 6 cylinder PG dosen't have oil cooler lines and it just has holes in the bell housing for cooling. Your little six cylinder will really like the extra gear...I have given away every powerglide I have ever owned. Later

Dave

If that's an aluminum-case Powerglide, find a drag racer or round track racer to sell it to, and you'll get enough for it to buy a couple of 350's. They really like them, and the prices are getting out of sight!
Jerry

ive heard that but theres been a couple in the trading post for a couple of months for 100 dollars apiece.

yes the 250 should bolt right up to a th350. th350's can be had for cheap. actually i am trying to get rid of one that i have.

If you were closer to WA state, I'm getting rid of a TH-350 for $50. Just need it gone. Junking out the truck, and want it gone... Was a runner at the end of 2004, engine died, truck sat....
Garry K

Sounds like I want to go with the th350. This truck was a front mounted motor, so I will have to change the mounts, I could make them, but anyone have a suggestion on who sells these motor mounts? I would also assume I would keep the existing bell housing mount for the tranny. Should I add another for the th350?

The 250 Chevy and the 350 Chevy engines use the exact same motor mounts, and there are lots of places selling motor mount kits to put a 350 in a 47-54 Chevy Pu. Hope this helps. Garry K

the th350 will not use the bellhousing mount. you will need a tranny x-member for it. there are many vendors that sell them.

If youre gonna go that route, why go for the TH350 or PG when you could have a 700R4? I know some will trash 'em cos they have a bad rep behind big motors, but a Six banger shouldnt kill it, and trust me, you will REALLY appreciate that extra gear when you take it on the highway...

the only reason wouls be cost i guess. how much does a 770r4 go for?

and yes, OD is nice for cruising

Thanks for everybody's help! It turns out I was wrong about the trans, it already has a 350 and not a powerglide. Not sure what kind of 350 it is, I am going to take a look at it this weekend, so I should know then. Lot's of people including my father in law, who owns a hotrod shop are trying to talk me out of using and inline motor on this truck, and go with a 350. I have another 235 running in my 54' belair with strait pipe's that sounds better than any 350 I have ever heard. I guess I don't get the horsepower, and I can't buy my parts at Kragen, who care's. I'm glad my parts aren't in a store next to a plastic cobra head shifter.

Gavin, there are essentially 3 types of TH350. Short and long-tailshaft TH350s and the TH350C Which is a slightly different animal and uses a locking torqur converter. I don't believe the 350Cs are as strong as the generic 350, but I've never really tested them. Btw, you can tell if it's a 350C by the presense of a 4-wire electrical connector on the left side, just above the pan flange.

Imo, the best tranny to use is the short-tailshaft, plain-jane TH350. Same length as the PG, TH400, Saginaw 3 and 4-speeds (not sure about the SM-420) and the TH200-4R. The TH700R4 is 3 inches longer...and the TH400 uses a different driveshaft yoke.

That plain vanilla 350 is a sturdy piece and will generally last a long time....of course it's possible to kill any trans...but the 350 is pretty good. The last time I saw one blown up was when a "friend" was showing another guy how to "peel out" by doing a 5000 rpm "neutral drop." I don't know of too many transmissions that would take that kind of abuse for long.

hth,

The old first series 4 speed hydro (i.e.-1955 Olds)would-been there,done that;broke engines,axles,springs,drivelines,u-joints,but the tranny was there to the end.

1955 2nd series.350 motor from 1974 truck.700R4 tranny.Stock 3.90 rear.20 mpg on road.Oh yeah Edlebrock intake and 600 4 bbl.carb.