ejscarfo

Hey guys! I've been shopping for a new crate motor to install into my 85 and I'm hitting a brick wall. No one sells a GM crate motor that will work with the stock intake of the L98 (Jasper sells rebuilt motors though). I talked to guys at Summit and Jegs and both are telling me none of the crate motors they sell will work. My mechanic buddy suggested getting the GM Targetmaster long block but I can't seem to find that. I initially thought the entry level GM crate motor with the 2 piece seal (part #10067353) would work but I'm told the intake won't bolt up. Does someone make a TPI intake that will work with that motor?

With that being said, I am sure someone here has dropped a crate motor into their 85 and can give some advice along with part numbers and where they bought it. I do have heads from a 91 C4 and the intake to go with it that I was thinking of using in conjunction with the ZZ4 short block JEGs sells but by the time I factor in all the parts, etc., I might as well get the ready to run Ram Jet motor and can the original TPI setup. Or if I could find an inexpensive short block to bolt those 91 heads and intake that to, I'm in business, provided everything, once put together, will work with the parameters of the 85's PROM (I don't know anyone that does chips anymore).

So.....suggestions?

VikingTrad3r

subbed

aklim

In what way will it not work? IIRC, there was some issue about the intake manifold bolts having different angles. If that is all, slot the manifold bolt holes. Plug holes might be slightly different. Not sure. Ask them WHY it won't fit.

leadfoot33

im going to be dropping a gm 604 crate engine into my 87, in one of my previous threads they talk about intakes that will work with the heads that come on that motor, there was one from edelbrock i think and someone else said to get an lt1 intake and modify it but i dont recall completly. im going to go with the edelbrock option easier and more just bolt on and go.

aklim

Also, could it be because the oil pan might have the dipstick on the other side or whether it is a 1 piece or 2 for the rear main seal?

bjankuski

I am not sure why people are telling you that, what you need for a direct bolt in is a 2 pc rear main seal block, with passenger side oil dipstick and standard bolt pattern heads. (the corvette's came with standard bolt pattern heads, the camaro's and firebird's had angled center intake bolts). The GM engine you listed will bolt in fine, it has all the proper parts to slide in and work. The only thing I will tell you is that you will lose some performance with that engine, the cam is smaller then stock and the compression is lower then stock, i would expect low 200's for HP with that combination.

Buy that crate engine, drop your 91 heads on, change the cam to something similar to the stock L98 cam with a little more lift, burn a chip and now you will have 250 HP, and drive like stock.

ejscarfo

So if I drop on that engine as is and install my intake system, do I need to have a chip burned or will the stock one work? I don't care about losing HP, the car is a weekend cruiser. I just want a reliable motor.

aklim

Probably not. If it is the same, it will. Otherwise, to be sure it runs right, you have to bring it to a dyno-tuned place

bjankuski

The stock chip should work just fine.

aklim

If the numbers are right, that is about a 20% drop in power. Is the chip able to compensate for that much of a change? Others have said that certain cams will be "close enough" to stock for the ECM to compensate which is why I am curious if it can stand that radical a drop. What is the approximate window of compensation? Some have said 10%. Not sure. Thoughts?

Tom400CFI

Should be no problem.

bjankuski

The 1985 car is a MAF car, so that means it is measuring the amount of air entering the engine at all times and adding in the correct amount of fuel for that airflow so it will work fine. The MAF cars are much more forgiving for engine changes and usually only have to be tuned for much larger cam installs where the idle need to be adjusted and injectors are no longer stock.

Side note it is will be about a 10% drop in power, the engine in question is very similar to the 205HP TBI truck engines, I would suspect that the TPI intake will add more torque and similar to slightly more HP to the TBI manifold that was used on the truck.

slow-vette

Are the crate motors you are looking at coming with Vortec heads? That is the only reason I can think of as to why your intake won't bolt up. If that's the case then you can buy a TPI base made for Vortec heads from Scroggin Dicky and get a nice little power bump as well. Otherwise the advice that the rest of the group is giving about a short block and bolt on your 85 heads and intake would work as well.

aklim

Didn't know they were that forgiving. My SD car didn't totally agree with the Superram and headers. Ran with more SOTP power but had some rough edges till the chip was reprogrammed by LPE. Didn't show issues with the header installation but I think the Superram was too much to adjust.

Thought that it was 250 and when you said low 200,i rounded it off to 200 hence my 20% figure and thought someone said that the MAF can adjust till after 10% when it might start to show up.

Good to know

ejscarfo

I can deal with a 10% drop in power. Like I said, the car is a cruiser. I will probably add to the motor later on once I have a good solid base, i.e. my 91 heads, etc. I already have a ported intake & plenum ready to be bolted on that can probably get me close to the 230 HP of the stock motor. But right now, I just want a dependable, drop in motor to start. Seems like the GM #10067353 crate motor will do the trick.

vader86

I don't see any reason why the stock computer setup will not work with that engine. Crates won't make the same power as listed once you slap TPI on them, but the engine works.

All you need is what has been said, pass side dipstick, 2 pc rear main, standard pattern heads. A Gen 1 SBC is a Gen 1 SBC. Usually I'd recommend just getting a ZZ4 and throwing the TPI on it and being done.

ejscarfo

The description does not say they are Vortec heads, just cast iron. Here are the specs from the Jegs website:

•4-bolt main with 2-piece rear main seal
•Nodular iron crankshaft
•4.000'' bore x 3.480'' stroke
•Internal balance
•LT1/LT4 powdered metal connecting rods
•Cast aluminum pistons (dished)
•8.5:1 compression ratio
•Hydraulic flat tappet cam (.383"/.401" Lift, 194 / 202 Duration @ .050", and 112° lobe separation)
•Cast iron cylinder heads with 76cc chambers
•1.940'' Intake / 1.500'' Exhaust valves
•1.250'' diameter valve springs
•1.5:1 ratio rocker arms
•3/8'' pressed-in rocker studs
•Block is compatible with left or right side oil dipstick (Requires Plug for Unused Side - sold separately) - p/n 809-14091563 left side plug; or p/n 809-9421743 right side plug
•4-quart oil pan
•Oil pump, oil pump pickup and oil pump drive shaft installed
•Includes timing tabs for a 6-3/4" or an 8" balancer (balancer not included)
•Recommended spark plug: 14mm thread, .460" reach, 5/8" hex, tapered seat, projected tip (AC Delco p/n 065-R45TS, Autolite p/n 417-144)
•Not Intended for Marine Use
•Requires p/n 809-19299222 or p/n 555-23605 Oil filter adapter (not included)
•Not Intended for Marine Use
•No core charge

aklim

What would it cost to rebuild your motor with the aluminum heads

ddahlgren

It begs the question to start what is wrong with the engine in the car did it blow up or just timed out/worn out?

ejscarfo

The motor is just worn and tired. At 155k, I feel it's done even though I know there are small blocks out there with well over 200k on them. I bought the car 12 years ago with 130k and it was in rough shape then. I brought it back from the dead so to speak so I think it's time.