if anyone can help me figure this out eveyone knows that in 1986 t/a's lost a lot of horespower due to emissions and i was thinkin if u could swap valvetrain from a 1989 lb9 tpi to a 1986 lb9 tpi if u can swap valve train what do i need like the heads and the camshaft and all the valvetrain? and if i can bore my 305 lb9 tpi to a 350 tpi is it possible to bore my 305 to accept 350 pistons and will the 350 crank fit with out a lot of modification if any one has done this or has any experince let me know it will save me a lot of money and isntead of swaping the whole motor for a 350

 

A 305 cannot be bored to a 350. If you want a 350, you have to swap one in.

 

where do you live, and don't tell me "Earth" either... ... now how is this that you lost power due to emissions?

 

oh alright so i would have to swap motor and computer and done deal right or there is more steps involved

 

i live in Lancaster CA...well in 1985 the horsepower output was prety high even on tpi cars and then in 1986 they droped because of sum emission that i have read and then in 1987 they went up again but now looks like ima have to go 2 the junyard and find me a 350 L98 with factory oil cooler lines and take it apart 2 see if it needs any repairs

 

Emissions had very little to do with it, starting in 86 GM put a smaller cam in the lb9's with the auto trans, which is mostly responsible for the drop off in hp.
There are plenty of camshafts available that will up the hp without any mods, or breaking the bank.

 

Like the guys have already said, the switch to the "peanut" cam in 1986 was the reason for the reduction in hp. And LB9s only got an auto trans in 1986, so all LB9 engines got this cam.

Unfortunately, all LB9/autos continued to get the "peanut" cam throughout, at least, the MAF years, which would be through 1989. So even if the valvetrains permitted, and you could swap the 1989 cam into your 1986 engine, if that 1989 engine came with an auto trans, then you'd just be swapping the same cam, and all would be for naught.

Like John said, there are plenty of aftermarket cams that you can buy that will give you much better performance anyway, so you'll know what you're getting and that it'll work.

Or if a 350 is what you want, then just go for that, and build what you want... keeping in mind the CA "smog police," of course.

 

oh i didnt know that how much would a street/strip cam would cost or what would u recomend

 

yeah i m kinda thinkin of puting a 350 L98 TPI and just handing my 305 to my cuz and he will rebiuld it just hit like 200,000 or so and its gona be going in his 93 s-10 but if i were to swap the 350 i would just need the computer and that woulb be it or is there other components i would need to swap along with the 350...im thinking of finding 1 in a junyard so if i find a prety complete car what would i need to get keeping in mind that im taking a chance that the motor im getting could be trash but its ok cause im going 2 school at UTI and they give discounts on many parts like rebiuld ect.

 

The nice thing about a stock LB9 and a stock L98 from 1986 to 1989 is that they used the same MAF system, so the MAF, the ecm and the wiring harness for an L98 are the same ones your car already has. So changing from an LB9 to an L98 in your '86 should go well, about as close to plug-n-play as you'll get. But you'd have to change the PROM inside your car's ecm, because it will require a 'tune' for a 350. But if you change from your current MAF system to the Speed Density system used in '90-'92, then you'll have to change all of that. It wouldn't necessarily be difficult, but it would be more complex.

Choosing a cam is almost personal. There are many that will work well, depending what you want out of your engine, and the costs of a swap can vary a lot, especially if you change other valvetrain parts. Using Comp Cams as an example, new cams cost around $300, but you can often find better prices and good deals on "hardly-used" cams in the classifieds.

You can go from "mild-to-wild." Hey, there IS another use for that phrase on the internet lol! But the cam should be "computer-friendly" for CA emissions. So I'd recommend studying cam specs; talking to people/cam manufacturers about your wants and needs; and two of my favorites: get a "dyno" program for your computer(they're fun to play with and pretty accurate when you use real data); and checkout videos and sound clips to hear how different cams idle.

But at least if you find an L98, its stock cam is will do until you get your plans sorted-out.

 

ok lets say that i went to the junkyard and pulled out a 350 L98 and and The whole ECM/computer would i still need to reprogram the PROM u were talkin about or would it be a plug and play like u said

 

this would be plug and play, taking into consideration that the current fuel delivery system did not change...

 

If you find an L98 in a junkyard car(and that probably won't be easy, by the way), and if it's an '87-'89, then you wouldn't need the harness and ecm because they would be the same ones your car already has in it. But you would need its PROM out of the ecm, if it's there.

But if the L98 you find is a '90-'92, and you wanted to use the Speed Density intake system it has(getting rid of the MAF system your car uses), then definitely take the harness and ecm(hopefully with the PROM still inside) because you'll need all of that, and none of it is interchangeable with your car's harness and ecm. But if you wanted to keep using the MAF system your '86 uses, then you wouldn't need the harness and ecm from the '90-'92. But you'd still need to get a 350 PROM for an '87-'89 or have one custom-made, if you can't find a stock one.

But assuming you do find all of that in a '90-'92 car, yet you planned to keep using your car's MAF system, it wouldn't hurt to take all of it anyway, because if you ever decide to convert to the Speed Density system in the future, then you'll already have the harness and ecm that you'd need.

But again, unless you already have a lead on all of that in some junkyard, it's probably not going to be easy to find it. So plan to make regular visits to all the junkyards you can, taking parts as you find them until you eventually have everything you need.

 

thats cool im defenetly gona look for sum if i get lucky in the junyard

 

the prom is it like a chip that needs to be put in there or do u have a pic of what u are talkin bout cause im kinda confused about the prom part