Okay, I have my 92 Camaro RS with a V8 305 tbi. I've had this car for over a year and I absolutely love it. But now it is time for upgrades. I've been saving up for a new engine all winter and have a total of 4000 dollars to spend. I am buying a brand new crate engine from gmperformanceparts.com and it is the base 350. My question is that will my 700r4 auto transmission be able to handle the 350? I don't think there is a problem, but I am just making sure.

I read the guide on 305 to 350 swap that bmonte made, so I'm not ill-informed on what is going on.

PS: I am buying the 2000 dollar crate engine, it isnt hopped-up or high performance.

Thanks

 

Can it handle it? Technically, yes. I don't think that the $2,000 gmpp crate motor will put any more stress on that tranny than your 305 does. But if the tranny has had a hard life prior, it may be almost time for a rebuild.

 

Well, my car has 140,000 on it right now. I am just wondering if it is worth it to buy a brand new motor. Maybe I should just spend half that on one from craigslist? And then I would have more money left over in case my tranny bit the dust.

 

It just boils down to what you want to do with your car. Obviously you are looking to upgrade a daily driver to a tad bit more power because you aren't talking about major upgrade for power. A 700r4 will hold that 350 depending on the condition of your transmission. Even a stock rebuild would work on the tranny. If you want major power, look for a built one.

 

Welcome aboard thirdgen.org.

I don't think the base 350 crate engine would be much of an upgrade over your 305. It's low compression, of the '85-earlier type, poor flowing heads, flat tappet cam, more leak-prone 2-piece rear main seal and perimeter-bolt valve covers - pretty much the only thing that would be an upgrade would be the displacement.

Your 305 probably isn't in that bad of shape with 140k miles on it if it has had decent maintenance. Similarly the transmission. You might want to consider other upgrades first, such as exhaust (about a $1000 undertaking, done right). That alone will help out your LO3. Then, a 350 might actually do better.

Take a look at the "budget 350" sticky in the top section of the TBI forum. That would make a noticeable difference over your 305, and would be much better than the base GM 350 crate engine.

 

If you are doing a 350 swap, buy a shortblock and change the head, cam, intake, etc. Like 57kid said, upgrade that 305. Lots of guys on here have. If it's not using oil, knocking, ticking, smoking, etc, Build it up and save the rest for something else like a huge buildup later. You won't be happy with a stock 350 85-earlier in your car for all that money.

 

If it were my daily driver, I'd probably stuff half of that motor money in the bank for a rainy day (for a future tranny rebuild in case it dies on you) and then mod the 305. I know that sounds like something a parent would say, but trust me I've been there...(spent several thousand on a crate motor and took it to the track 2 weeks later to test it out and lost 3rd gear in the transmission on the way there.)

I didn't want to come right out and rag on the motor you were looking at buying, but in all honesty, I'd mod the 305 before getting a low-performing 350. Five7 said it best...that 350 won't be much of an upgrade for you at all. If you do exhaust mods, they will give you more power now and will swap over to a 350 later if you decide to buy one. Heck with exhaust mods alone I'm sure you'd have more horsepower with the 305 than if you just bought the 350 crate motor by itself.

 

That does make sense, thanks.

 

I just don't see you guys' logic in how the engine I have now is 170 hp, and you guys say i wont get much performance difference than the 350 with 290 hp. Thats like a 60 percent increase in HP, plus then I could do all the tbi mods with the 350, and a new exhaust.

 

I just don't see you guys' logic in how the engine I have now is 170 hp, and you guys say i wont get much performance difference than the 350 with 290 hp. Thats like a 60 percent increase in HP, plus then I could do all the tbi mods with the 350, and a new exhaust.

 

Its a 290hp engine with a good carb and a free flowing exhaust, and keep in mind it's probably rated at fly wheel horsepower, not wheel hp. Factor in 15% drivetrain loss, poor flowing factory exhaust, etc. and the power output is greatly reduced.

 

Exactly. Well, almost exactly. It is a case of apples to oranges power ratings. Both are flywheel HP, but the 170 is net HP, meaning as-installed in the car. That 170 HP is more like 240 the way the crate engine is rated. The factory LO3 exhaust is really restrictive, while the dyno set-up they use to come up with the crate ratings is open headers. To say nothing of the TBI itself.

And, for what it's worth, you didn't say you were considering the 290 HP version. There is a 260 HP version, which is identical to the 290 HP version except for the cam. The difference in price between those two is a lot more than what a good cam & lifter set would cost you. And, I would call the 260 HP version the "base" version.

So, some bad assumptions on my part. But, still not too far off. $2k is a lot of money for 40 HP. Exhaust, cam, and tuning will get that for you out of the LO3.

 

wow if the 305 was really rated at 240 fw, then i may be making a mistake. The whole scenario is that I always wanted to get more power out of my car. I assumed it was just a slug, and i thought if I dropped a 350 in it, then it would be faster and no questions asked. But I think I am wrong. Its just too much money for a 17 year old to deal with. I mean, I have the money, but thats a hefty chunk of my wallet i'll be driving around.

Plus, If I did it at school, it would be sitting in the shop room ( where other kids have classes as well 9-12) vulnerable to anyone who wants to mess with it. It would be a month+ long project aswell so I'd have to borrow my parents car, which I always hate doing.

So, like you said, I could do the budget mods and be happy because I did it, and like you guys said, save money in the long run.

My shop teacher says "dont go to forums they are full of crap" and he advocates the new crate engine totally, but now I see that he might be a little mistaken.

 

Doesn't sound like your teacher knows all that much.. especially if he thinks that just slapping that crate engine in there would be the magic bullet to break into the low 14's..

 

can you really do that much to a 305 to be worth it tho? i have one as well and was considering replacing it next season with a 350 swap.

 

It depends on what mods you're doing, if you're smart you will do stuff that will work with the 305 and later on work well with a 350. There is a TON of stuff on our cars that can be improved before you should even think of swapping in a new engine. The factory exhaust systems are extremely restrictive, headers back exhaust is the single cheapest horsepower per $$ mod you can do. Subframe connectors improve handling, reduce chassis flex, prevent/stop stress cracking, and should be considered for any F-body car before trying to put any power through it. Those are just a coup,le things you can start with that will put you on the right track to consider an engine swap in the future, do a search or ask around and there are a ton of other things you can do, some of which are free.

 

Careful, don't take that too far. What I was saying was if the 305 was dyno tested the same way crate engines are, it would probably put out around 240 HP. Basically the difference in displacement (45 fewer cubic inches, 45-50 less HP). I have never seen a dyno test of a stock LO3 with carb & velocity stack, open headers, no accessories, etc.

Going the other way, the increase in displacement going from 305 to 350 would raise the LO3's 170 HP to about 215 net HP - but, probably less, because the restrictive exhaust and TBI would cost the 350 more than the LO3 would gain from being freed up with headers, carb, no accessories, etc., on the dyno.

 

Yea, i see you guys' wisdom. Well I am going to start with a header-back exhaust system as well as a new tbi unit. That will be the best in transferrable. And, because my car is getting up there in miles, a used 350 motor would be just a reasonable later. There is plenty of people parting out z28's in my area with 350's.