My '86 Z51 A4 has 145k+ miles on her. She uses some oil and water, and my oil pressure drops to about 6-8 lbs at a hot idle in drive and I am using fresh mobile 5w30 with 1 pint of STP.

Anyway, I want to keep the original TPI and maybe do some port matching work to the new engine. Here is my question.

What would be the best aftermarket long block lets say a (383) that would provide me with the most low end torque. Keep in mind, I hate speed, I love chest caving, eye bulging low end toque. I take this car on beautiful, well paved east TN mountain roads, but I never get out on the interstate and try and see what she will do top end. I want a small block long block that will bolt right in and give me the low end torque close to a late '60's L-71, L-72, or L-89 big block........

Any suggestions?............thanks

 

Dart 400 shortblock.

Bigger is better.

 

 

I agree that bigger is better, i went to a 383 setup as the scat forged steel crank, rods and forged pistons was just too cheap.

Another note the oil you are using is for modern engines, the cap should have a 20w40 or something similar?. You can get some thick oil that will stop that oil use.

Water use is usually a bad pressure cap heater core or head gasket.

 

For some more low end "fun", while the engine is out, install a 2,000-2,400 rpm lockup TC and a TransGo shift kit...

 

I have always loved the stock converters on the early c4's. Don't they already have around a 2k stall stock? Also, I would like for someone who has made a swap to another short block to give me feedback. I would like to run my stock aluminum heads, have a multi angle valve job done, install new springs that go with the new cam, match port the intake and runners, and bolt them on the new shortblock.

My plans are to build a reliable sleeper with stock wheels, fairly poor paint, etc. But I want the car to have incredible low end torque. I may change the rear end to a dana 44 with a 3:07 gear. I am thinking 383 because I am on a fairly tight budget..anyone?...............t hanks

 

If it were me and you have to keep the TPI get the base ported as much as possible, some aftermarket runners like used asm or similar if you can find them. That extra stroke will give you tons of torque. That intake is SO restrictive making it larger will ADD torque everwhere dont let anyone tell you it wont. Just finished up a stock GM base and got 244 cfm out of it up from 211. Nice gain and is plenty for some worked over L98 heads
Took a lot of doing though. Even getting 20 cfm out of them is a real chore

Go farther than port matching the heads get some seat and bowl/short turn work done youll get the most gains there. Too many start making the runner entry as large as possible youll go backwards or your machinig guy will if thats all they do.
Youll be lucky to get 220-230 cfm out of the L98 heads wtih stock valve sizes but if you just want some bottom end that should do ya. Start upgrading to real good heads and shorter runner intakes and tuning it gets real pricy real fast. Keep it simple

Id also add about 15-20 deg duration to that cam and some type of header you should have a reliable tire roaster on your hands that looks factory; roller tip rockres should be fine no need for full rollers if your cam isnt huge

Anyways my .02 youll hear a lot of different opinions just get your package well thought out the first time and stick to your plan

You can do all this without spending a ton. It will cost some...but effective for the gains

 

ZZ383 crate engine, TPiS mini ram, & new prom & your good to go with 425 ponies at your right foot.