Cudos to the free thinkers. I grew up on 80's SCCA trans am racing when gm got their 90 deg. v-6 approved with a250 pound weight break. It was originally a good idea for the low budget teams because you didn't use up as much tires and brakes and less stress on the driveline in general. Then chevy won the title in 86 with W. Dallenbach using both v-8 and v-6(chevy 4.3 based) motors depending on the track. Then things started to accelerate towards high dollar teams spending $40000 for buick v-6's that would turn 9500 rpm for 1 hour then explode. By 1991 SCCA had reduced the weight difference to 125 lbs or even less thereby effectively eliminating the 6 as a viable option.By the way the Buick was an excellent motor but with the 6 allowed as much induction as the 8, there was obviously flow capacity to twist it higher. My point in all this is I built a 4.3 with 229 heads which I would, some day like to put in my 86 t/a. It wouldn't pass emissions,but reading some of the other posts sounds like alot of the "stock" v-8s around here wouldn't either. It just sounded like a cool idea,better handling, better weight balance, more room in the engine bay and at a target output of 250hp it should be quick enough to surprise some people. My nostalgia may outway my pocketbook in completing this so if you want the motor, ask, I'll give the specs. It's taking up room in my Dad's basement and he's moving.

 

Well the other 4.3 thread turrned into a bash post.

I'm just wondering if the smogers would catch a V8 to 4.3 conversion, I bet if you did have a TBI 5.0, poped in a TBI 4.3 and got a long 4.3 fan shroud from an EL Camino 9 out of 10 people wouldent catch the change because they look similar.

 

true, and on the other perspective of this going from 2.8L to 4.3L wouldnt be super hard would it be ? cept for bellhousing and maybe exhaust manifolds ? or no ? motor mount locations ? definitely radiator swap needed..
hmm.. maybe not an easy swap

good luck'

 

Why does everybody say the radiator needs to be swapped??
Most if not all V8 thirdgens came with 2 row radiators just like the V6's.........

 

stiffert: I really would like the specs and part numbers for your engine. I've seen a couple of good builds in hot rod mags the past couple of years for the 4.3, and have done some of my own research on what types of heads can be used. I really am going to put a 4.3 in my 91RS 'vert someday. It originally came with a 305, now has a 355 in it...I want it more for a cruiser than a speed demon now, hence, the 4.3. Any idea on exhaust manifolds? How about headers from S-10's? Did anyone make headers for the 4.3 monte carlos? If neither of these will work, I may try to use stock exhaust manifolds from an S-10 or other 4.3 car/truck. Anyone else who has done/wants to do this swap, please post info on how to get it to work properly. BTW, you shouldn't need a different radiator at all, especially if you started with a V-8

 

I got the bottom end out of an '87 inboard boat(omc) that galled a piston.Did a decent polish and deburr job on the crank and rods. Installed .020 over KB hyperuetic(whatever) pistons with single trough type valve relief.Important note: cheap pistons have a lower height so they will fit in a block that has been milled,this creates a dead spot in the combustion chamber where squish is supposed to be occuring.Irregardless of comp ratio this is inefficient as incomplete burning of charge is the byproduct. The machine shop I dealt with did the research and found the Keith Black pistons to be the correct height and even then RC Automotive recommended we take a light pass off the block (@.005,can't remmember) to maximize squish. The heads are off a 229(@1980-84)enlarged to fit 1.94 and 1.5 valves,done on a Serdi machine which if you're unfamiliar cuts a nice blended 3 angle valve job. We chose the pistons to complement the heads to give about 10/1 comp ratio. No ccing was done just an educated guess. By accident I first bought heads from the 200cid engine produced from 78 to 80(?), these would not work because the holes for the water jacket came too close to the sealing area around the bore. The cam is a Lunati with .525 lift@ 1.5 rratio and 252 deg. duration at.050 lift, solid lifters. The intake is the Edelbrock performer designed for square bore carb. Bought Bow Tie tall plain stamped steel valve covers. No carb(yet), stock oil pan and nothing special double row timing chain. No rocker arms,I was determined to buy roller rockers. No water pump.
The cam is really too wild. There are a few people making headers for that engine in the pickup etc. There is a company called Sanderson making shorty generic headers for hot rods.

 

Exhaust manifolds besides aftermarket should come from a GMC Safari/Astro van or el camino, Some later (LOL) 4.3 elcamino exhaust is a standard truck type but the early ones will fit an Fbody perfect since the front half to the fire wall is the same as an Fbody. I made an El Camaro last year, Camaro front clip El camino back half so I know. The radiator is fine as is you just need new longer hoses and an ECM from a 4.3 Caprice "if TBI"

 

If I can find a good carbed 4.3 cheap I will do a 4.3 swap and not think twice since my Fbird is now my DD.

 

Heh, I sorta worked on an El Camaro earlier this year. I get the ticket and it says "89 Camaro" so I go looking for a Camaro. I look and look and look....no Camaro to be found. So I try to match the licence plate number.....I find the matching plate on an '86 El Camino!!! Yeah, now I'm confused.

So I pop the hood...5.7 TPI. I jump in the car...full Camaro interior. The guy actually registered his El Camino as a Camaro!!!!

Heh, then we told him to get lost 'cause we don't mess with modified vehicles.

 

I wanted to make a [80's] El Cutlass but no one wanted to help.

would of been a back yard hopty job but the car was free and I need to be able and carry stuff. Didnt have 500 bucks for an old truck but i hard a torch and a axe.

ended up parking it as the engin went fast, lady gave it away from a slight rod knock. with 7 quarts too much oil I was not suprised. yes 7 quarts too much , on top of the 5 it needs. All the fins had fallen out of the radiator so it got hot when driven long, so when it started ticking form being hot. [never bioled over] she just added more oil, and added more oil.

 

Let's see a 2.8 camaro frame mount looks identical to a 2.8 S/10 frame mount,So a 4.3 S/10 frame mount and engine mount would most likely make this a bolt in. The steering column on a S truck is much closer to the motor so I don't imagine any clearance probs(especially since the S guys use milled camaro manifolds for their V-8 swaps) V-8 radiator with a electric fan would work nicely. 85-86 Carb intakes of the 4.3 were Quadrajet patterned and cast iron(Heavy,tall,but what the hey,Cheap). 85-86 carb Distributors could easily be made to work as a regular stand alone by using the internals of a Buick even fire distributor. A nice edelbrock 500 or even 600 atop an adapter. My choice would be a 93-95 S/10 CPI engine(converted to carb) with a camaro five speed.

A good reason for this swap is frankly mentioning the word 350 makes most Yard owners jump the price way up. I have scored a 95 CPI 4.3 from a 4x4 S/10 for $350 because he had too many of them.

 

Only one thing, though; most of us are interested in the 1/4 mile. I still can't see going thru all the trouble to change out wiring harnesses & possibly fuel systems just to put in a 4.3... might as well go to the 5.7. Kinda reminds me of if we swapped in the 2.5l I-4 just because we could bolt on a supercharger.

 

Actually I think a lot of it could be testing good ole GM interchangability. Nah but it is great. I just can't figure out why the heck they didn't put the 4.3 in the f-body. 2.8's were just to small a motor to be pulling around the 3000-4500 lb S trucks and 3200 lb f-bodies. The trans usually went out early from overcycling D to OD every other hill. At least the s series finally got a 4.3. .

 

hey JRoy91RS, if you're lookin to ditch your 355 any time in the future, i'd be happy to take it off your hands! i've got the little 3.1 and am content for now, but i'd love for my firebird to scream.

 

I've had the same thought. In the overall scheme of things the 4.3 was probably too close to the base 305 in performance.GM needed an inexpensive option that wouldn't threaten sales of the v-8 models which had option packages attached,therefore higher profit margins. At least that's my theory.

 

Wow, where to start? Stiffert and SSC, thanks for the info. I had no idea that someone made some headers that will work. I think that I will stick with a hydraulic roller, since they are everywhere. Also, the Vortec heads flow very well on the 4.3...much, much better than any other 4.3 heads (stock). Go to S-series.org for more 4.3 info. they have a very good message board. Comp cams makes some really great hydr/roller cams for the 4.3, that work great with computer controlled 4.3's. Does anyone know if standard headers/intakes will fit the Vortec 4.3's? I'm under the impression that they will.

I do know that the 4.3's are a bulletproof engine. My family owns two 4.3 vehicles--a full size 91 pickup, and a 92 4-door CPI (vortec) Blazer. Between the two of them, they have nearly 400,000 miles on the engines with NO oil leakage at all. None. That speaks volumes for this engine's reliability. This is quite common for the 4.3, btw. GM did it right wih this big V-6...it's the only engine they still equip in their vehicles that's been around since the 70's, and for good reason.

TomP...I'm doing the swap into a 'vert. Just for something different and for reliability. Let's face it...a convertible isn't a very good 1/4 mile car out of the box. That brings me to my next point 90 firebird . The 355 will be saved for my next project...which will be a 1/4 mile screamer...but that's a couple years off. Gotta save up for some AFR heads and a supercharger... after I finish my Master's Degree...hehe. I've already got the perfect cam for a daily driver/quarter mile badass in the 355, but I digress.