V8 conversion question....headers & AA adaptor

[boost addict]

Will the GM block hugger headers available from man-a-fre fit a '94 LT-1?

I've heard there is an overlap issue but not serious. I'm new to both Chevy and Landcruiser but bound and determined to make it work. lol

Next question, my cruiser (1/79) came already equipped with a carb'd 350 and a TH350 tranny with the AA adaptor. Now I'm going with the 4L60e and I was wondering if the AA adaptor is going to mate up to it? Don't slam me too hard, remember I'm new.

Thanks in advance guys!

 

[1973Guppie]

call manafre and AA........

Noah

 

[nuclearlemon]

fj40 or fj55?

 

[boost addict]

This is on a 40.

Chose not to call the manufacturers, you guys here seem to have more of a grasp than most of them. lol

 

[zebrabeefj40]

You will need a new adapter to make the 4L60e work with the Cruiser t-case. The TH350 adapter will not fit.

Pretty sure there are a set of stock OEM "block hugger" manifolds for the LT1 motor. Corvette application IIRC; for sure NOT from a Camaro/Firebird. I'm also pretty sure you can get a block hugger header from Summit or Jegs for the LT1 and that it will be cheaper from them vs. Man-e-Fre. I would guess the Man-e-Fre parts would fit your existing 350 but not quite work with the LT1.

HTH,
Nick

 

[Brian in Oregon]

You might want to contact Advance Adaptors. They carry several types of headers for Chevy smallblock into FJ40 conversions.

I don't know what the difference is between my basic 350 and an LT-1 as far as exhaust ports go. I'm running their 717011 inside the frame center dump headers. They also offer a 717015 for standard ports with angle plugs, 717016 for D-ports, 717043 for Gen III.

Here are photos of the 717011 headers on my 350. AA warns that they may run interference with the stock steering gear box, and this is advice that needs to be heeded.

You can see clearly in the above photos that the rear two tubes are extremely close to the steering box. In fact, the installer the previous owner used dimpled the tubes slightly. The tubes are likely rubbing with engine vibration and movement. I need to move the entire engine/tranny/transfer over to the right about 3/16" at a minimum. And that's with the dimples. Without the dimples, plan on moving the engine over 1/4" to 5/16". If you use the 717011 header, figure this is a given and plan ahead.

There are no problems on the right hand side for clearance.

I like the header setup, but the issues with steering box clearance needs to be addressed.

When the day comes that these need to be replaced, would I reorder them? Maybe. My preference on an application like this is for cast iron exhaust manifolds. I haven't found any I like, though, except for some very expensive custom rodder style center dump manifolds. The cost might steer me back to these headers.

 

[my64fj40]

My preference on an application like this is for cast iron exhaust manifolds. I haven't found any I like, though, except for some very expensive custom rodder style center dump manifolds. The cost might steer me back to these headers.

What is wrong with regular GM ram horns

And I would be interested in seeing some pics or a link of the expensive custom rodder style center dump manifolds..

 

[Brian in Oregon]

What is wrong with regular GM ram horns

I'd like something a little more free flowing. Supposedly there are larger flow versions made, but I haven't seen them yet. And I'd like to know how they work for spark plug boot and wire clearance for heat. I'm not a GM expert. I finally got into small and big block Chevies in the last three years. Prior to that was all Ford (mainly FE big block) and Mopar.

 

[dgangle]

OK, not to pirate this thread but WTF is the difference between a carb'd '70-80's SBC and an LT/LS-1 port/header dimensions? Are they different? If not, why not use the tried and true Ramshorn manifold? If different, what is a source for these besides custom headers?

To borrow a saying from Mark, I am a carburated man in a fuel injected world.

 

[my64fj40]

I'd like something a little more free flowing. Supposedly there are larger flow versions made, but I haven't seen them yet. And I'd like to know how they work for spark plug boot and wire clearance for heat. I'm not a GM expert. I finally got into small and big block Chevies in the last three years. Prior to that was all Ford (mainly FE big block) and Mopar.

There are 2.5" center dumps that were on vettes..

Brand new and cheap http://www.1aauto.com/1A/ExhaustManifolds/Chevrolet/Corvette/1AEEM00169/287615

Ramhorns are known for being some of the best flowing manfolds



As for heat Get some of those inline boots and they are fine

 

[my64fj40]

And BTW those 1aauto aftermarket ones that supposed to be beefier than stock..

They really are, I got some 2in and compared them to the GM ones I had around and they got alot more mass to them.

 

[Brian in Oregon]

I was looking at those in an old PAW catalog. They stated they fit 327 and had generator extentions on them. I would assume then that ordinary 350 heads would work just fine, and that the generator extentions would not get in the way of the alternator (or power steering for those running it)? And PAW wanted over $300 for the pair, and that was over five years ago.

 

[mo_fj40]

i have to disagree with the th350 and the 4l603 adapter being different.

if the 4l60e has a 4 bolt tail housing it is exactly the same as the th350. if the 4l60e has the 6 bolt tail housing, then it wont.

there arent any differences in the shaft dia and spline. it is also the same as a 700r4 (4 bolt).

i just put an adapter from a th350 onto my 700r4 then upgraded to a 4l60e.


i would find some ram horns over block hugger headers any day. they do flow well and you wont have the motor mount clearance issues that some create.

 

[Lynden]

I'm running an LT-1 in my 96 Impala, and it has regular old long tubes from an 81 model camaro on it. The only difference in the ports is the LT-1 is D shaped, and the sbc is either round or square. The ram-horns will work fine, just get a decent aftermarket gasket and bolt it down.

The stock LT-1 manifold uses the outermost bolt hole in the front and rear, whereas the sbc headers/manifolds use the inner of the two bolts. If you look at the head you'll see what I mean.

 

[my64fj40]

I was looking at those in an old PAW catalog. They stated they fit 327 and had generator extentions on them. I would assume then that ordinary 350 heads would work just fine, and that the generator extentions would not get in the way of the alternator (or power steering for those running it)? And PAW wanted over $300 for the pair, and that was over five years ago.

They should bolt up to 350 heads just fine..

The mounts shouldn't be in the way and if they somehow were you could probably just have the mounts point toward the rear of the vehicle..