new to the forums

[hobsiscool]

Hey guys, I'm new to the forums...i've got a 81 Sierra Stepside...4.1L I6...So i've been trying to search the forums a bit while at work and when I get home, but I still have some questions. First off, I'm in the Birmingham, AL area, so anyone around in the area that has some expertise, let me know, I may be needing it. Specifically in the body area (need some body patches welded in) Second, I know absolutely nothing about carburetors, my daily driver is a '05 Subaru Wrx Sti, so an older truck is a new venture for me. I keep seeing where a 4bbl carb will fit on my engine, but I don't know which particular one would, or any of the specifics. I also MAY have the chance to swap engines. We also have a 87 pickup with a rebuilt 350 in it...trying to talking my dad into swapping with me. It's fuel injected, however, so how hard would this process be? Sorry if any of my questions sound dumb, but that's why I'm here...to learn and educate myself. Any help would be greatly appreciated...With all that said, I'm glad to be hear and love checking out everyone's rides.

[seanconnery]

Fantastic, and welcome to the boards. I also have an 81 Sierra with a 4.1 inliner, but mines a fleetside. I'm also not very familiar with carbed motors either. To help you with your question, If you're swapping over to a fuel injected engine, I think you have to perform major work to the trucks wiring harness. I don't think our trucks came with any sort of computer, so adding a FI engine will entail adding the computer and all related stuff. I think there is some threads about swapping to FI somewhere around here.

[old Rusty C10]

welcome to the board... first off you can do the swap but its alot more than just motors it will be mounts and harnesses etc.. not worth the headache IMHO but im sure others will disagree... How about some pics?

[hobsiscool]

I'll post some pics as is when I get home...currently i'm just tearing it down bit by bit and salvaging waht's still good and deciding what I want to replace...so probably in a week or two it will be a rolling cab...right now I THINK i may have a blown head gasket...that's why I was considering engine swap, in case it was more serious...what can be done to my stock engine? I dont know a whole lot about it, haven't found a whole lot of write ups on it so far either...I notice a lot of people have it, but not near as many parts are sold for it from what I've seen.

[D13]

Assuming it has an integral head (the intake and head are 1 part) there's not a lot you can do without a head swap. Fortunately this is easy to do, just need the parts.

FI on the L6 is pretty much TBI not port fuel due to the heads.

If you find a head gasket problem be sure to have the head pressure checked and milled, the integrals like to crack and warp.
The 6 can be made into a monster but it's a lot cheaper to build a 350 for the same horsepower.
Search this forum and the engine forum for '250' and you'll get a start.

[hobsiscool]

My engine looks like the one in this thread...

http://67-72chevytrucks.com/vboard/s...ghlight=inline

is this the integral head? If no, what route could be taken then?

[72BlckButy]

to the board from Mid-MO!!!

[Palf70Step]

The only 6 available in 81 was the integrated head, at least for the 4.1L. The engine shown in the link is an old style with non-integrated manifold/head.

As said you can convert it over. Truthfully if you want to go with FI on a straight six, look at Clifford's setup. As others mentioned trying to convert TBI to an inline is a BIG pain and I doubt you'll see any worthwhile efforts for the time and money you put into the adaption. The Clifford EFI though seems to be worth it's weight if you want FI vice carb and want to stay with a inline.

[hobsiscool]

Originally Posted by Palf70Step

The only 6 avaialble in 84 was the integrated head, at least for the 4.1L. The enginee shown in the link is an old style with nointegrated manifold/head.

As said you can convert it over. Truthfull if you want to go with FI on a straight six, look at Clifford's setup. As other's mentioned trying to convert TBI to an inline is a BIG pain and I doubt you'll see any worthwhile efforst for the time and money you put into the adpation. The Clifford EFI though seems to be worth it's weigth if yo want FI vice carb and want to stay with a inline.

where did 84 come in to play? I have the 81...I must be missing something...i'm on the fence now...obviously swapping from carb to FI wouldn't be fun, so we can scratch that...but now i'm on the fence of whether to build the 250 that's in it (probably more money) or swap in a carbed 350. I'm also fairly certain i have the non integrated head...how can you tell? What 4 barrel carb fits on the inline? I know of the book for this engine (can't remember the name) that I need to get, but I was just trying to get some input before hand. Thanks for all the replies thus far though.

[arkracing]

You would have to get an aftermarket 4bbl Intake Manifold to swap a 4bbl onto the motor (Assuming that the motor is a not-integral head). They show up on Ebay and here on the board from time to time for about $100-150 used. Summitracing has Offenhouser's new I believe.


If you're looking to get performance out of the 6 cly, it will take a lot of $$$ compared to the typical Small Block 350. 350's should be plentiful in the Carbed variety, and speed parts are much cheaper (intake, headers, etc.)

The TBI 350 could be used, but it would be easier to buy the intake that bolts to the TBI heads and uses a Carb.

[Hoods69BadBowTie]

Hey welcome to the boards from MT. I would just try to find a carbed 350 SB and drop it into your truck.

[D13]

The picture shows a separate intake (silver) bolted to the head (dirty brown). An integral will have one solid casting carb to head, not a bolt on like the one shown.

No 4bbl fits the factory. The only factory 2bbl is on an integrated. All the others , including early integrateds, are 1bbl.

These motors are not drag race machines. They are extremely reliable and relatively cheap to operate. I have had 2 go over 200,000 miles with nothing other than oil changes and spark plugs. One went 425,000 miles without the head or pan off. (I must admit that at the end it was eating a quart of oil every 50 miles, only 1/3 of which was leaking). They are not hipo monsters.

If the budget is tight and you're not especially mechanical the cheapest route is to use Craigslist and swap in a complete 305 or 350. be sure you get all the pulleys and brackets including the block side motor mounts. It should drop right on the frame mounts.

But 6's are more cool.

[Cherub]

Welcome to the boards! There is alot of knowledge here. I used to have a straight 6 in my pops 82 step, but i burned that up and put a 350 in it. it was nice but the straight 6 3speed tranny didnt transfer the power very good. Good luck with your truck bro.

[87 STEPPER]

Welcome aboard i have some limited experiance with the integral 6 and if it were me id go with a 350 as others have mentioned you can convert it over but for a guy that drives Wxr Sti i dont think you will be to impressed with a i6 performance output.

There is a member here that lives in your city his board name is Captkaos he is also a site vendor here and he can help you out with alot of the body panels you mentioned he runs a new parts house called http://www.73-87chevytrucks.com check him out if you havent allready.

Good luck

We need some pics!!!!!

[manimal]

Welcome from sunny SoCAL.
-Lance

[Captkaos]

Welcome from Birmingham.
Swapping the 87 TBI motor over would be a undertaking, but if the donor is running it would be fairly intuative.

[84 400]

Welcome!

The 350 swap would be the cheaper route and a 350 Carb would be even cheaper and easier.

That said a done up 250 or any chevy I6 is just down right cool. 350's are boreing and comon while a nicley done 250 is unique and diffrent. The only problem is that the 250 will cost more to get to the power level of a built 350 so the choice is yours.

Also I might be wrong but I am almost positive your truck did not come from the factory with a non integral head six but I could be wrong. At that I didi not think they put the 250 in 1980's trucks or even late 70's trucks for that matter. I think GM came out with the V6 around 1984 in the full size trucks

[87Lowrider]

Welcome aboard!

Just a thought:

Earlier this year, I took the 350 out of my '87 and swapped out the intake and TB for an Edelbrock Performer Intake and 1406 carb. It's going in my '78 camaro this winter. You'll need a fuel pump too but that shouldn't be a big deal either.

Kenny

[hobsiscool]

alright guys...do i have integral head or not? here's some pics..

[Palf70Step]

Your driver's side view is the main one and it looks like you have an integral head from what I can make out of the intake manifold features.

[Captkaos]

Hard to tell from the pics, but by default any 81-up will have an integrated head. Integrated means the intake manifold and the cylinder head are cast as 1 piece.

[rod86]

welcome from australia... all dumb questions are excused - coz you drive a WRX and coz theres no such thing as a dumb question... ill let the guys in the know how help you out with your I6......

[OJOE]

welcome from montgomery,al

[84 400]

I am thinking it is an integral head from what I can see in the picture. IF you had another shot with he aircleaner off we could tell you for sure. Eather way that is a SWEET looking stepside you got there. And the non inegral head swap is pretty common with lots of good info.

[grinch4om]

love the wheels!