78T/a

Hey Guys

Well I'm in a pickle...I have a tough decision to make, and I will try and make this as short as possible. I have a 78 Trans Am, it's my weekend warrior street/strip machine. Anyways 2 years ago I caught the drag racing bug and Im hooked, and going faster is the only option, so that is why last year i went and bought a stroked 455 pontiac engine, making around 580/580 crank. This doubles the output of the original mild built 400 so like i had planned I was going to go faster. That being said, Ive always been a huge fan of the infamous LSx based motor and have always wanted one. After spending time on this forum and reading about all the different set-ups and whats possible with these motors, Im almost convinced I want one in my 78T/a...almost!! And the big deciding factor in which im sure you can all can attest too is MONEY. I got a hell of a deal on my pontiac motor, and im not sure I can replicate the output for the same price. And Im "almost" willing to accept the loss of power, because thinking ahead the LSx based motor seems to make alot more sense, its current, they are everywhere and they joys of fuel injection. Im assuming 10 years from now its going to be alot easier and "cheaper" to maintain and upgrade compared to my Pontiac motor which are alot harder to come by and expensive and not mention bad on gas. So in a case of "what would you do", do you think its worth me selling the pontiac engine and work on setting up a nice driveable LSx car. Im going to focus on getting a strong transmission first, so not much will be left for an engine so its going to have to be stock to start, and thats what is making my decision tough.

Anyways sorry for the length...I just dont want to make the wrong decision because Im trying to make my money stretch as far as possible.

Thanks
Mike

PS...what are guys with cam/gears/converter doing in the 1/4

j99fbody

iTrader: (1)

i would go lsx, you can make a ton of power out of them and they are much lighter then the old pontiac motors so you will shed quite a bit of weight up front.

78T/a

Hey j99

Thanks for the reply and seeing the picture in your sig its good to hear an answer from someone with an old fbody whos done the swap..and good point about the weight, never thought about that....mind if I PM you sometime about how to go about the swap

Thanks
Mike

j99fbody

iTrader: (1)

i would be happy to help anyway i can

bad_408_vert

iTrader: (6)

Without a doubt and for every reason you mentioned. go lsx!

My6speedZ

iTrader: (18)

Would you be converting it to a carb set-up or adding EFI?

78T/a

Im reading on that stuff right now, EFI would be the overall goal but im thinking in the sake of getting an LSx engine in the car the cheaper route would be start carb'd as thats what my car is set up for now

RPM WS6

iTrader: (3)

I'd probably stick with the Pontiac engine. It's going to be hard to match the torque output you listed of your 455ci engine with a stock displacement LS1 unless you use N2O or blower/turbo. And if you're going to build a big stroker LSx engine, it's going to cost a great deal more than what you'd ever be able to sell your Pontiac engine for.

Don't get me wrong, I love the LS1s in my 4th gens, but I prefer old engines in old cars. Just my opinion.

My6speedZ

iTrader: (18)

Check out Schwanke, they sell harnesses and you can get them with the PCM and everything.

94LT1TA6spd

Everyone and their dog runs an LS platform car.... Dont anyone take offense to that comment, it is true, they are great motors, but I like it when people do something abit different!

Youve already got the 455, I say run it till it gives up on you.

What did you pay for the 455?

Starz T/A 17

iTrader: (6)

While I can see some of the reasons for going with a LS1 such as more efficient, FI, etc. I doubt that it would be much cheaper. The swap costs are going to be fairly large, and I don't see the parts being any cheaper.

78T/a

Hey thanks everyone

Im realizing the more I read stuff it's going to be expensive just getting an LSx in the car let alone make good power....I'm considering boost and going with a truck 4.8 or 5.3...but that's in the long run....tough call...

94 LT1....I paid 6500 for the 455 and I failed to mention its stroked to 474 and forged guts..a good friend had to sell it to pay off some debt...so i couldnt pass it up

My6speedZ

iTrader: (18)

I'd keep it then

raysadude

iTrader: (11)

OP have you ever considered LQ4/9 instead of LSX they are cheap and have similar parts with LS1/6 engine

quicksilver383

iTrader: (3)

Really? I think you answered your own question “I got a hell of a deal on my pontiac motor, and im not sure I can replicate the output for the same price.” Also, you’re asking here on LS1tech about an LS swap so your answers will be biased. Go over to performaceyears.com and ask the same. Your answers will be biased as well but the other way. Whatever money you think you’re going to save now or in the long run will be negated by hurting the value of your T/A not having a PMD engine. The 455 can go as fast as you want if you make the right choices. Do the swap and I bet you’ll just be in the same situation after the swap, thinking about what to do next to go faster. How fast do you want to go? For your LS mod bug you could work on your truck, just a thought.

RPM WS6

iTrader: (3)

Agreed. With the crank torque numbers that the OP listed, the 455 (474) should be making over 460tq at the rear wheels. You aren't going to get a factory displacement LS1 engine to make that kind of torque with heads/cam/bolt-ons alone, and frankly it'll be hard to even match your current horsepower numbers with a stock displacement LS1 (assuming no N2O or boost).

LS1s are great and can make big power, but a performance built 474 cube V8 has a massive displacement advantage that can't be ignored. Smaller displacement, higher revving engines CAN make just as much power, but it'll be at higher rpms and with less torque (NA), which isn't always as fun for a street car. I know that your goal is 1/4 mile racing, but if it's not going to be a dedicated track car then I think your current 455 (474) will be more enjoyable to drive and faster stop light to stop light than a basic heads/cam/bolt-ons LS1 engine in the same car. Again, it's going to take more cubes or a power adder to get an LS1 up to the torque level of your current engine, and that's going to make this whole swap deal much more expensive (not to mention all the other parts you'll need for a swap and FI conversion - if you want to go that route).

78T/a

Hey quicksilver

Yah I realized it would be biased I just wanted an opinion from all you guys who know these lsx engines from top to bottom and could tell me what kind of work I would have to do in order to have something atleast comparable to what I have. And yes the truck will see some work, but in the mean the car has to get done first

I know exactly what they would say on Performance Years, hahah if it ain't about a pontiac they dont care hah

By the way, love the quote in your Signature..hahah cant wait to say that to a friend who thinks his civic is fast lol

78T/a

Good points all well taken, and what you have said is what I was looking for answer wise. I wasnt sure what it would take to replicate what I have, I was expecting it to be more expensive as I did receive such a good deal for my 474.

But all things aside, if I was willing to sacrifice the power of the 474 and a faster 1/4 mile in order to have a more efficient and driveable car, which at the end of the day is what I do most with it, late evening weekend cruises are my favorite(girlfriend to) an LS seems to become a lot more appealing. And I guess that brings up the age old argument of do I go faster and lose the driveability or sacrifice speed for a mild powered cruiser...

quicksilver383

iTrader: (3)

Hey 78, yeah I saw you were over at PY also, good to see you there. Don't forget these cars were new one time and drove just fine. My Lemans is all stock and I dont do anything to it. Pump the gas when I havnt started it in a while but otherwise I just drive and it requires nothing special. Heck, I would easily go so far as to say it's neglected that way. I'm not sure what your goals are for efficiency and drivability but I would get it out of the 474 one way or another. Good Luck!

My6speedZ

iTrader: (18)

What is it exactly that your find unsatisfactory about the 474 that you would improve or would be looking for a ls1 swap to improve?

If I missed this I apologize.