I am new to building motors and selecting the proper components for the right application. I am just starting to build a 1949 GMC pickup that I intend to get running and driving this winter for next summer. I bought a 1977 Chevrolet Concourse (4-door Nova) as a running and driving donor car. It came with a 305 small block with only 55,000 miles on it. But I also have the option to pick up a early 70's (70 or 71) sbc 350 with 194cc heads and a 4-barrell intake for real cheap. The question is....Do I stick with the 305 and just run all the drivetrain out of the donor car or do i build the 350 and swap the motors? Now I should mention, I will be pulling a 1953 14' Terry Rambler camp trailer with this truck to Bonneville next year but I am traveling quite a distance so economy is definately a goal as well. Any and all advice is welcome. I am not a sbc guy so this stuff is new to me, I just know they are very reasonable to build and my goal is to get this truck on the road and have fun with it. thanks Andy
I would go with the 350 over the 305. They cost about the same to build but the 350 will give you the torque to pull that camper. They're pretty much the same on gas mileage too (not to great but decent).
305s get a bad rap, but their a decent motor with good torqe. 305 HO heads are 194s. Put a different cam in the 305, a nice carb, and it'll run good for a long time, just dont expect 10 second ETs at the track. I like em cause their cheap!
They cost about the same to build either way...like said above, the 305 HO heads are great for flow, but are getting harder and harder to find, but all and all i think most here will prefer the 350 cause of the bad rap the 305 does have. That being said, it all comes down to what YOU want to do.
I used a Crane cams 272 H grind hydraulic flat tappet, and an edelbrock performer intake. great motor. Just dont wind em out to 6700 like i did, cause the rod bearings dont like it
How about running the 305 as is, and decide if you want to build the 350 after you get the truck going and see how the 305 does... and I'd be really surprised if a 77 nova has only 55k miles on it, it's possible I suppose, but it's way more likely that it's 155k. unless you owned the car for the past 32 years and can personally vouch for the mileage, or have really good documentation to prove it. A 155k mile 305 is probably getting close to being worn out, a 55k mile motor would not be.
I'd get her running with the low-mileage 305 and get everything sorted out, then if you still want more grunt you can build a nice 350 and swap it in later. Who knows, you might find the 305 is all you need. Pulling a trailer requires torque, not high rpm power, and torque comes from stroke. The 305 and the 350 have the same stroke. Granted, it is a bit short of the 350, both power and torque, but pulling your trailer you might not notice the difference.
I have made this mistake twice with a 307 and a 305, if you are going to spend any money on performance parts go with a 350.
I say the 305 deserves more respect, after all, it shares essentially every part with the 350, save heads and pistons. What's in a piston? Ask a 283! The light weight heads are really to blame. Set those aside and get some decent closed chamber heads from a late model or the aftermarket and you can build a potent combo. My favorite so far is using a carefully milled set of 58cc 305 heads and a properly decked block with virtually everything else from a 325 HP, 327 c.i. motor. I guess it was well over 10.5:1 compression and made scary torque.
I rather have to agree with 51box, If you plan to put performance parts on it and hop it up a bit go with the 350 to start with. If you plan to keep it the way it came out of the car with maybe an intake and carb swap and not much more the 305 will get the truck down the road and pull the trailer ok. I ran mine with a 250 six 3 speed and Nova rear end for close to 100K with few problem outside of the fact that it was a bit low on power out on the long highways where you want to make mile. With that drive train it would be pretty much the same a hooking that little trailer behind the Nova and taking off down the road. A little low on the long hills but otherwise fine. Without the trailer it will cruise at highway speeds all day long and probably pass a few more gas stations than the high horsepower boys can before stopping. The good thing is that you can put it together with the 305 and run it without laying out a lot more cash for the time being and then if you want a 350 later it is an out and in swap and away you go down the road with more power.
Hey Bro! just my opinion, I have used both the 305 & 350 in projects and I would say go with the 350 hands down.
Rebuild kit's for the 350 are cheaper. Once bought a 36,000 mile 75 nova 4 door, factory buckets, for 300.00 from an old woman. I don't think she ever had it serviced.
Ive done both engines. The 305 and 350 are the same engines and even share the same blocks most years. Only diffence is the bore and stroke. Meaning the 350 has a 4 inch bore and more stroke. You'll be happier with the 350. Ive built a 305 using mostly 350 parts and the torque just wasnt there like a 350 has. Gas milage will be about the same since the 305 has to work just alittle harder to pull the camper compared to the 350.
heh...that's news! I thought they both had the same stroke, and the bore on the 305 is so much smaller that the block has to be a different casting.
Chevyshack is on crack! Squirrel, you have it right on..Same stroke, different bore..lol..but no really, its true. As for sharing the same block? Never seen this before...the only sbc blocks I know of that are the same casting #'s are some late '69 castings 302, 327 and 350's, these are all same bore though...soooo ya, good crack there in Florida I guess.
Take the 305, put a RV cam in it for the towing and drive the tires off it. When it starts giving you trouble 200,000 miles down the road then put the 350 in it. My 2 cents.
if the 305 runs good, go with it. Good ignition, about a 268 dur.-450 lift cam , intake and carb change with headers. If you can score a pair of HO heads for it, it will run good and have decent low end power
______________________________________________________________ There is an old saying....."There is no replacement for displacement".... build the 350
If the cars runs and drives good, all the usual checks (compression, leakdown, etc.) are good, just use all the bits from the donor to bolt the sucker together, and run until it drops. Save any mods for when your rebuilding that 350 into a torque monster.
Also,even though they have the same stroke, the cranks are still different due to the 305's pistons being lighter. The cranks should not be interchanged w/out machine work.
I got one from the junkyard for $100. It was swapped out of a boat and had a decent cam, deep pan, windage tray, etc. It is still powering my 54 Ford F250. It is weak compared to a built 350, but it will not die. I even tow my boat to the lake, over 5000 feet here. I have had a 350 on the stand for almost 10 years now waiting for that damn 305 to even burn a little oil.
no one can tell you when an engine will die. If all things are equal, airflow is king- 305's have puny bores and wont breathe for real grunt. If you need to build one- pick the 350. If you are happy with the 305 as is, then use it. You can always swap them out- Chevys are good like that.
If you got a motor out of a boat, it's most certainly got forged internals (boats and planes always get the good stuff) I always jump on boat stuff when available
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