Here's the deal I have an 86 4.3 I wanna make like 250 horse this motor is going in an 85 Toyota 4x4 / I wanna run 1.6 full rollers an roller cam , cam I'm looking at is a comp cams 18-124-4[37] grind # 268h , is there anything special I need do there since the 86 blocks wasn't a roller cam / the intake look like an high rise cast iron are they any good for making power an what shorty headers are good / now heads how much of power gain would infer with the newer vortec heads any thing I needa do to run the roller rockers on my heads or the vortec heads , what would be a good intake if I went with the vortec heads or if I stayed my stock heads .... So should I be able to hit my goal of 250horse out of the older 86 4.3 an any advice would be greatly needed ill be turning 40in swamper Boggers with the Toyota 5 speed an 4.88 gears so more power an torque are always helpfull

 

So you have a 165 hp chevy astro engine that's one of the earlier 4.3 designs and you want to make 250 hp trying to mix and match later design parts?? Hope you aint planning on doing this n/a with a carb. Good luck cause you gonna have your work cut out fer ya.

Since you got so many questions I'm gonna try to break it into groups.

Cam, short answer no.

Intake is junk but you can't use it with vortech heads

Factory manifolds have been proven to flow enough to support 300-325 hp. Headers take your pick but being in a toy most likely gonna be custom one offs.

Good luck, you gonna have a ton of time and money in that boat anchor when it rattles itself apart in a mud hole. Even if you done all the mods listed I only see 200-210 hp. Hope you don't plan on keeping the toy toothpick axles with those 40s.

 

So I can't run a roller cam , but is the cam I mentioned any good for power

I knew if I went vortec heads I'd have to buy an new intake quick is fine I'd get a Brodix or elderbrok , an yes I'm doing this carberated 4 now propane in future

How much of a gain would I get with the vortec heads

The roller rockers are do able just gotta change the studs correct

Ill just run my manifolds for now then

I under stand its gonna shake but my 4 banger did to , my axles are built with chromoly axles and cryoed gears runnin the bigger v6 gears I'm not Worried bout my axles at all

 

ok im gonna be the one to ask the age old question.

why not just a v8? you could get a running 96'+ vortec v8 for about 300 bucks at a pick n pull,toss a carb/intake on it and run a msd ignition box. have less then 1500 in it and haul *** in the tiny toyota. its more cost efficient .

 

Traded my 22 r for the 4.3 an Chevy to Toyota bell housing I'm out no money so that's why I'm going the 4.3

 

you can use the same bellhousing from the 4.3 on the 5.7. if you are out of money forget the 4.3 build as its going to need alot of modifying and custom parts to hit a reliable 250hp. Its just not cost efficient,especially if you are on a budget. Remember you are going to need a decent exhaust setup too. thats even more money. Sorry to bust your bubble man. Good luck with the swap.

 

Ill be happy with anything over 200 horse honestly / tell me what i gotta do / I'm might be picking up a set of Sanderson headed

 

See,your problem is this. that engine you have now is about 165 hp. the heads are swirl port heads that were made for low end torque. They dont flow well up top where you need it since you are going to be mudbogging the yota. So now you have to get some true 96+ vortec heads. This is getting costly already since the heads like to crack so if you get some used ones you gotta pay to have them checked. The cpi heads (from 92ish to 94?) might be a cheaper solution. They have a tad bit more power over the tbi heads and is a direct bolt on and you can even use your tbi manifold. You need to have them checked for cracks as well. The 96+ heads you have to buy a manifold since the bolt angles are different. Weak spots for the older 4.3's are the heads,and the tiny cam. You need to replace the lifters too if you are going to be putting in a cam.

 

The heads have been changed the casting numbers show there the 92' models are they decent for now till I get the vortecs ,,,,, where do they like to crack so when I go look for them ill know where to look

The cam i speced out in my origanl post comes with lifters

Now the roller rockers / I know they'll free up a lil power an give more valve lift with 1.6s will that be to much with a .450 lift cam

 

Your trying push a V6 4.3 and get an additional 100 more horses out of?Sell it get a V8 and do the swap.Save yourself the head ache V8 parts are cheaper.Alot of guys attempt to do this in the long run its not worth it.By the time it would be all done you will probaly sink 2k in the engine alone.