I've had Chevy engines all the way from early 6's to the 454 I have now. There is nothing wrong with the 305 you have, and the fact that it is already there is a serious argument. Having said that, when it comes to pulling, bigger is always better, but the downside is more operating cost when you aren't pulling. How often will you have the trailer hooked up? What topography will you be driving in? If the only time the truck goes out is with the trailer in tow, then stick in the biggest lump you can make fit. Cubic inches are easy horsepower. If however, you are driving this thing more without the trailer than you are with, keep the 305. It can be made to pull a surprising amount of weight without breaking your budget, and it's smaller displacement will help you with economy when you aren't towing. One thing to consider is a gearing change to help the little engine stay up in it's power band better. A change of just a few teeth will make an enormous difference in towing capacity. Still cheaper overall than a big engine. justmyarrogentopinion
you guys blahblahblah about 305 cant tow / bigger is better / get a 350 are so full of shit your breath stinks. I ran a FULL 95 SIZE GMC extended cab with a EFI 305, 5 speed MANUAL trans and 3.43 gears. I searched a long time for this combination and could easily pull any trailer that my hitch was rated for. the manual trans negated the power loss an automatic takes away. 20 mpg was no problem either. Its all about the combination. the 305 is an efficient engine, with a relatively small bore pushing against a long stroke. moderate increases in airflow really wake it up. something like a comp cams 260 or 4x4 cam is perfect for the 305. the early ones suffered a bad rap (somewhat diservedly) due to low compression and smog cams. they are a SBC just like any other and respond well to mods, just like any other.
I second that, on both common sense and the suggestions. If he had said " I have a 283 and I want it to be a stump puller" a number of these reactions would likely have been different." I figure some of these folks will say to my comment " Nunh unh", but whatever, you know it's true. People love to hate on the 305. Is it classy? No. Is it utilitarian? Hell yes.
Some folks obviously live life in the slow lane and like to waste money. Well move over and give that wasted money to the ones that need it! B.T.W.: This is NOT a smart ass remark..... This is a smart and intelligent remark. A 305 needs a boat load of money just to make a mediocre engine out of it. If the only 2 choices to build on were a 305 and a Briggs & Stratton, my vote would be the Briggs. You'll spend less for about the same amount of performance.
Your comparison, is ridiculous at best. And does nothing in answering the OP's question. Negative. FNG.
The favored stroker combo for the 305 (3.75 inch crank for 334) is similar in bore and stroke to the 331 Caddillac...and no one here's calling that engine a waste of cash. like the man said, its all in the combo. But, price a 350--not the Mexican rebuilds spoken of in the posts about worst chevies ever, but a good 350 with a warrantee. that's the cash target you have to come in below, for it to be worthwhile. transmission ratios is also an issue, but I missed where you mentioned what you had. Are we talking powerslide, TH350, or 4spd OD tranny? running a 305 at higher RPM could wear it out sooner...but then again, if its bolt on parts you'll be using, you could just get a shortblock 350 and swap on, which means you won't be sinking more $$ into a second 305. knurl the original pistons' skirts, etc, spend the big bux on airflow and other parts that transfer to a 350. remember something about those long stroke engines--they accelerate the rate at which the piston gets yanked down the bore. The sudden increase of cylinder volume can cause a pressure drop sudden enough to cause increased filling at low RPMs, as the air in the intake is at atmospheric pressure and the cylinder is vastly less so in too short a time as soon as that intake opens. its not vaccumm or boost, but the result can be similar at low RPMS, plus the leverage may push the exhaust out faster at same RPM...all other factors taken into consideration, natch. Its why long stroke 6 cylinders "made so much torque" but lost it at higher RPM, along with the inability to move something that long at high RPM without serious occilation going on. cam accordingly. roll the dice, takes you chance, eh?
Not to beat a dead horse but the rods and crank for a 305 are the same as a 350 so i'd trade the block for a 350 block 4 bolt main block. Bore it .030 over and you'll be much happier. But if your dead set on using that 305 block (because that's what you have) bore it .060 and get a set of 601 H.O. heads an R.V. cam and a good flowing intake. I don't know if a set of vortec heads would work with those small bores or i would suggest that too!
Correction, 305 and 350 DO NOT share same crank...different part number but same stroke....But not the same. Counterweights are different.
kracker36-----why would I want to ruin a good truck------if I went with a 351 I would'nt be going at all.----ha ha !!!!!!!!!!!!
Build a 334 stroker. It's a 305 block and a 400 crank. 3.75 bore and 3.75 stroke, flat top pistons, and a 60 cc chamber head with 1.94 valves and a rv cam. I built one for a suburban compared to a stock 350 it had more torque. Nice thing was with a full time 4x4 with 3.40 gears it was getting 14-16 mpg.
Just went back and read the whole thread and saw your post. Your right on the piston speed. The long stroke brings the piston speed up, and makes the engine react to cams at a lower rpm. It makes a longer torque curve as well. I have had 2 334 strokers. One in the truck, and the other in a nova. The nova had a 3.08 rear with a 700r4 trans. It carried the car very well and at highway speed it never dropped out of OD.... Had lots of power. I have to say though if you're on a tight budget build a 350. Parts are cheaper, and unless you have a late 2 peice rear main block I don't trust the 305 blocks lifter bores. They had alot of problems in the late 70's and early 80's...
Let's not forget that more cubes normally means more pulling power. Let's also not forget that a 305 is a small block Chevy, the most hot rodded motor in the world. And while it normally will not overpower a Chevy 350, It will overpower a 262 SBC. I have a 305 in my 56 Chevy and it produces plenty of pulling power. Specs
I run a Comp cams 252 Duration cam with a 2000 stall non-Lock-up Converter (TH 350), in my late model El Camino (Daily Driver)..... I also have roller rockers (1.6 rockers on the Exhaust only, because the heads are stock). Installed, is an Edelbrock #1406 carb that I re-jetted and I leaned out the metering rods (Need to buy the kit). It pulls my ( M/C & trailer) well .
Now that everyone has gotten themselves all wound up let me salt this discussion a little. In about '91 I scabbed together a mud truck to drive back to Mexico. Short on cash I found a Short bed 84 Silverado that was rode hard and put up wet, then I went out to the local wrecking yard and managed to buy a wrecked '84 4x4 that the fella had been killed in cheap because of the whole bad Ju Ju thing. The wreck had a 305 in it and had belonged to the local guy that built about everyone's roundy round engines and this was his car hauler/driver truck. It had a 305 that he had tweaked. I talked with his living business partner about the truck and he said that all he had done was clean up the heads by blending the bowls, throw on a cast iron spread bore intake and rebuilt Q jet that was laying around the shop and a melling RV cam. I didn't stress the engine too much I was only running 35" tires in the mud and muck in the rain forest then too and from the border twice a year. The only time I ever got it into low lock was to pull someone else out of the mud. I think that with minimal mods that the 305 in my last Mexico truck did just fine. It certainly had enough low end grunt to opull me though places that the average off roader would just dream of.
Uhhh... no. TORQUE is pulling power. and a long stroke small bore motor will make torque at low RPM *where you need it for pulling* versus a large bore/ small stroke of equal displacement.
What kind of trailer, what kind of tow vehicle? If it is a fairly small trailer and the tow vehicle isn't a monster a 305 should handle it. Remember this is supposed to be a budget rebuild for an economy motor. How about an overhaul (rings, bearings, valve job) plus an RV cam, small headers, 4 barrel carb? Should give good pulling power and not too hard on gas. If you are going to spend money on a stroker kit and all that high falutin stuff it would be better to buy a 350, or even a big block if you can find a good deal. (there are some good deals on truck big blocks out of buses. They are no good for hot rods but great for trucks and towing).
It will never keep up with a 350 but I made some drastic improvement in my OT pickup by doing the following. Removed the OE catalytic perverter and replaced it with a modern high flow cat. Big improvement. I already had a turbo muffler on it. Sounds better now, too. Removed the air pump. Not much noticeable change. Changed the ESC to a standard HEI distributor and after I got it dialed in, this improved the throttle response and acceleration. I won't call it a slug now but it's not a stump puller either.
Right---the 305's crank is balanced differently than a 350's due to the 305's different piston weights vs. 350 pistons; the 305 crank would have to be rebalanced to use in a 350 block. 1) The main question, to me, is how heavy is the trailer, how often will you tow and what terrain---lots of hills or flat? i would suggest concentrating on precise ignition tuning and timing and very precise carb tuning and then maybe add headers (which will benefit regardless is you stay with the 305 or move to a 350.) The 305 will run better and provide more power than you might think. There again, gearing has EVERYTHING to do with towing. Will going lower seriously affect non-towing mpg?
Thing is you can gear it to pull, you won't go fast but it will still do the job. That's why those old pickups had a "granny gear" first. I'd take into consideration where you're going to tow, if you plan on going up and down a lot of hills in the mountains there, you may be more comfortable starting with a 350 just for the reason that those 50 cubes are cheap power. If it was up here and I was going mostly down I-90, that's pretty flat, I wouldn't even worry about the difference. In fact, something like a 472 Caddy may even be a better starting point for loads of torque. A 350 can do the job, buddy had one in a rollback truck and would sometimes haul one on the back and one on a trailer behind, but going up the hills to his place the manifolds would be cherry red by the top of the hill. It was about the limit for that motor.
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