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Blacksurt 03-27-2011 05:08 PM

1998 TJ small block chevy build
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Here is a few pics of my current project. 305 Chevy in a 1998 TJ where a 2.5 used to be. A little back story, about 30 years ago I had put a 289 small block ford in a MB model Jeep (sacrilegious I know) the radiator was bailing wired in, the firewall was cut out and patched with sheet metal you get the idea. Never give a 15 year old a cutting torch and welder. So I decided to do it right this time, my goal is a old school hot rod Jeep with plenty of low gears. Being it had a 2.5 ltr. it has 4.10 gears attached to a th350 with no lock and no overdrive it will not be a highway machine. I am just waiting on the transmission and weld in mounts from Novac to continue. I got rid of the PCM completely and am going with aftermarket all mechanical gauges. There were a couple of things I had to do to make this work, the fuel sending unit is 20 ohm full and 220 empty I used a 240/33 aftermarket gauge and just wired a 20 ohm resistor in line to bring it up to 240. Also with a carburetor being fed by a 49 psi fuel pump I put in a fuel pressure regulator to cut it back to 5-6 psi. I found an invaluable TJ full service manual on e-bay for 3 bucks (digital download pdf file).

Blacksurt 04-06-2011 04:00 PM

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B&M Z Gate shifter and block hugger headers.

solman 04-09-2011 04:06 PM

Looks great so far.

Blacksurt 04-10-2011 04:54 PM

Thanks, transmission and mounts are supposed to ship Wednesday from Novac.

cpisani89 04-10-2011 06:10 PM

very nice..i thought about swapping a sbc into my yj but dont have the money right now..looks good though

Blacksurt 04-29-2011 08:20 PM

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Finally got the parts form Novac, got the engine and transmission in today. Will probably fire up tomorrow. Novac weld in mounts worked great. I wasn't how much sag there would be after installing the V8, a 2" lift is definitely in the near future.....

VVCG33 04-29-2011 08:24 PM

I so wish I had the knowledge of how to put a motor in myself..

scgeek12 04-30-2011 01:33 AM

looks great, awsome job on the guages looks clean

n00bkiller944 04-30-2011 01:45 AM

Looks awesome! I love all of your gauges!

herbie 04-30-2011 01:46 AM

instrument panel looks fantastic nice!!!

Nuts 04-30-2011 04:28 PM

Did you fire it up today? I am thinking of buying a 350 (or the dauntless V6) jeep for my second vehicle. So your thread is really instructive. Please keep the updates and photos coming.

Blacksurt 04-30-2011 07:53 PM

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Got it fired today. Did not have to get drive shafts redone, transfer case sits about 1/2 inch forward of original. Cost of project just over 3k.

Engine 300.00
Gaskets-Timing gear set-oil pump-etc 100.00
Gauges 100.00 Oreily auto parts (everything pictured)
Fan 2500cfm ebay 75.00
Block huger headers 70.00 ebay
radiator 130.00 ebay
Transmission lines Jegs (braided steel kit) 130.00

+Hoses-fuel regulator-fuel line-fluids-fan relay-power steering hose- about 200.00

Novak: rebuilt adapted turbo 350, 23 spline input shaft np231, motor mounts, transfer case shifter and Freight. Just under 2000.00.

I will need a set of 6 cyl springs. Its saggin in the front some. Might just do a 2" lift (springs and shocks).

Project went like clockwork. 2 hours to position and weld in mounts. I advise tack welding them in with the motor in place then pulling motor up and then put beads all the way around. Don't forget to check radiator/fan clearance before you tack them in.

I rented a transmission jack and put it in from below. (about an hour). I know some like to put the whole drive line together and thread through the front, I couldn't do that due to the lack of space. I did all of this in my driveway with no garage. Long live the shade tree mechanic.

Blacksurt 04-30-2011 07:56 PM

Oh yea exhaust is going to run another 250.00. Flowmaster 40 duals out the back.

Blacksurt 04-30-2011 10:27 PM

Thanks, for the comments on the dash....Just ordered a set of 4.0 springs (ebay 50.00 shipped). From what I have been able to find out the 4 banger weighed 340 lbs, the 6 weighs 515 lbs and the 305 I put in weighs about 575. Take a little off for headers and the soon to be aluminum intake, the 4.0 springs should work fine. I'm not ready to spring for a lift kit yet, the 4.0 springs should work until then.

scgeek12 05-01-2011 09:26 AM

looks awsome, love the valve covers, had them in my first camaro a few years back -

Blacksurt 05-01-2011 07:27 PM

Nice, old school.

Blacksurt 05-14-2011 11:58 AM

Here is the Jeep running....finally got the mechanical speedo drive so all the gauges are working. Had to go with single exhaust flowmaster 40. we could have squeezed a pipe down the drivers side but it would have been to close to fuel lines. Put the 6 cylinder springs and 2" lift on as well.

YouTube - 1998 Jeep Wrangler TJ Chevy V8 conversion

Nuts 05-15-2011 08:58 AM

Nice building. You put in the 305 and probably considered the 350 as well. Was this because of the presumably better mileage on the 305 or size/fit considerations or for some other reason? I ask because I will purchase a second Jeep and want to do what you did here. Thanks.

Blacksurt 05-15-2011 10:33 PM

A 350 and a 305 fit wise would be exactly the same. I actually had a chance to get a 383 stroker (350 Chevy with a 400 crank 400HP) for the same money. I really didn't want something to radical, I will be driving it regularly and fuel economy was a factor also. 4.10 gears and 220HP out of the 305 is enough for what I wanted. If you are building a weekend warrior go for the 350...

Nuts 05-16-2011 09:59 AM

Thanks for that information, Blacksurt; the 305 sounds like what I need; fuel economy is a factor, right up there with the power of an 8. It looks like a weekend job when you have all the parts.

burton160w 05-16-2011 10:20 AM

What radiator did you get and would that also work with a 350? I like how thin it is and the clearance it's giving you between the fan and the engine.

Blacksurt 05-16-2011 02:58 PM

This is what I bought, bolts right in as stock. Keeps my 305 super cool. I used the Novac weld in mounts in the furthest back position, there was plenty of clearance. I went ahead and hung the motor where i wanted it then put the radiator/electric fan in just to double check before welding.
Jeep Wrangler 87-04 New V8 Conversion Radiator Chevy | eBay

Blacksurt 05-16-2011 03:09 PM

For anyone doing a build like this If you are going to be doing any highway driving over 55 you might want to consider a transmission with overdrive or consider changing out differential gears. Mine runs about 3500 rpm at 55, so forget about 75 for a distance. I built mine for primarily off road use so seldom need 55 even. It is fun to drive in town though, I could smoke anything light to light.

Blacksurt 07-18-2011 10:46 PM

Update: pulled out the 305 and put in a rebuilt 4 bolt main 350. Ran into some heat issues solved those with a 19" flex fan.

Durban 07-30-2011 06:47 AM

Looks good man I have an 88 yj with a 350 she a beast. Have fun try and keep it on all four lol.

Blacksurt 08-02-2011 09:16 AM

Dash wiring information mecanical gauges
I have had questions on the dash wiring so I thought i would go ahead and post.

I made the dash panel myself, I used a plastic air conditioner baffle laminated to some 1/8" plywood. I used leds for the turn signals and brights indicator (o'reilys). The fuel gauge was a little tricky as the factory gauge is a 240 full/ 33 empty sending unit. Use a 220/20 gauge and just put a 20 ohm resistor in line or use a rheostat with 20 ohm in its range(radio shack). Volt meter is easy just wire to a switched 12 volt. Oil pressure will connect right next to the distributor (towards the drivers side) on the back of the motor. There should be a place on the side of the head on the drivers side right behind #1 cylinder for the water temp, or on the front of the intake somewhere. As far as speedometer gos I used a mechanical which was a little work to make work, I had to change the sending unit on the transfer case (assuming yours still has the NP231) to mechanical, I found mine on ebay and I had to cut the dash behind the speedo to make room for the cable which is still tight. If I had to do over i would have just used the stock electric sending unit and just gone with an electric speedo. As far as AC I really cant help with that.

When you take out the stock instrument cluster there are 2 plugs. Here is the colors you need.

Tan=Right turn
Black/Lt Green=Ground
Orange=dash Lights
Red/Green=High beam
Dark blue/White=Hot Switched
Gray=Left turn

Along the drivers side frame rail(next to fuel lines)

From the fuel sending unit
Brown/Yellow=I grounded this one
Dark blue/Light green=to fuel gauge

Dark green/White=is the positive to fuel pump.

Black=ground for fuel pump

As far as making the dash panel I made a cardboard template to make sure all of the gauges would fit. The completed cluster is screwed to the dash trim from the front, you can see in the forum pics. I used a aftermarket tach which is bolted to the change tray in the top center of the dash.

Hope that helps....

Blacksurt 01-15-2012 02:15 PM

Update 98 TJ
Jeep now has a rebuilt Chevy 350 4 bolt main, just installed Crane 100052 Cam. Over 5000 miles on conversion with no problems.1998 Jeep TJ Chevy 350 Crane 100052 cam - YouTube

TreeClimber1 01-15-2012 02:36 PM

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Sweet build.

Wish I would have found it earlier.

I've done a couple V8 swaps into Wranglers. If your fuel pressure regulator craps out, consider just pulling the pump out of the tank, and replacing it with a piece of hose. Then you can use the mechanical pump off the engine block. That's how I ran my YJ with an AMC 401 before I went to fuel injection.

On my TJ, I built a similar guage setup, but with electric guages. Had a buddy cut a piece of steel, then recessed it into the OEM cluster, behind the original plastic. Then installed the guages.

If you still have what's left of your cluster, want to sell it? I'm trying to build another like mine for a buddy.

Blacksurt 01-15-2012 03:26 PM

If you still have what's left of your cluster, want to sell it? I'm trying to build another like mine for a buddy.[/QUOTE]

Cluster looks nice, I sold the original on ebay....

klpossinger 01-18-2012 02:47 PM

TreeClimber1, that is one really nice custom cluster! What gauges are they?

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