Will this work??????

[72longstepper]

Looks like a great price. What problem would I have putting this in ?
https://spprecision.com/products/che...BoCFoIQAvD_BwE

[AJC]

First it's a one piece rear main seal, so a new flex plate or flywheel is needed. along with a new oil pan. Second the 96 and up vortec heads will require a new intake manifold. I think the 87 -95 tbi heads might too, as they changed some bolt angles. Third center mount valve covers are needed. Forth you might not have a fuel pump mount. Don't know if they except a non one piece rear main seal block.

now if you decide to do it go with a 96 and up block. You will need to go to a electric fuel pump and new intake manifold, but the vortec heads are the best flowing cast iron heads chevy made. You will also get a hydraulic roller cam. which is a nice upgrade.

Others will hopefully fill in what i missed.

[Jrainman]

Not saying this is a bad deal ,but have you considered just getting a brand new L31 crate engine from Gm , it will come with the oil pan , timing cover and balancer,also backed by a GM warrenty. also is that a 2 bolt main or 4 bolt main L31 and does that price include delivery ,I would call them for more details on this remanumactured L31 engine. I am saying this because I bought a New L31 4 bolt main crate engine from GMparts247.com delivered to my door and after the GM rebate I was all in for $1,750.

[rcazwillis]

We put a L31 in Zane's 71. Things not mentioned yet:

Harmonic balance spacing is different. There is a tabbed wheel the crank sensor uses that goes on after the timing chain, but before the cover. Spaces the harmonic balance out to line up properly. Not sure if hb is different or crank is different.

Timing chain cover is different on an L31. Plastic and there are fewer bolt holes. Some have used steel covers and drilled the additional 2 holes in the block.

There is no mechanical fuel pump rod hole. So electric is required. Be smart on electric and have a safety mechanism in place to turn the pump off if the engine dies. We used an oil switch designed for this function.

The roller cam has a hardened distributor drive gear. The distributor you use has to have a different gear than traditional sbc. Melonite or something like that. A standard HEI gear will wear out quickly.

This conversion would be easier if you sourced an used engine for bits and pieces.

[rcazwillis]

Rocker arms are also different. They have a guide stamped in the tip to keep the arm on the valve. Obviously, they are included in this example, but if you plan to upgrade those, expect more money than standard.

The different intake has other issues too. Like no allocation for divorced choke coil mount. Have to do something different for choke.

There is also a requirement for a vent from intake to water pump. Our pump was factory and had a port in the top that lined up for a hose to go to intake. Evidently, the engine will overheat and build pressure. Might want to check into that issue.

Stock vortec heads will support about 0.47" of lift. Easy machine work will relieve the restriction. Might want to check on that too. A moderate roller cam for these engines will exceed that quickly. They also have a reputation of pulling rocker arm studs, so screw in is recommended with any upgrades.

The temp sending unit hole in the heads are smaller. So your sending unit won't work unless you get one of the machined own ones available here on the board.

[truckster]

I removed the reluctor ring on the crank and used a Cloyes double roller chain. Ditched the plastic cover for a stamped steel one - the two missing holes are for pins, not bolts, and they're really not needed in my opinion. Harmonic balancer is a stock '72 350 unit. I replaced the cam with a GM HT 383 cam - good for approximately 330 HP and 400 lb-ft of torque. I had the stock springs in the heads replaced with stock springs from an earlier 350 - spring rate of approximately 130 vs 100. The rockers that come with the heads are fine.

You'll need an intake manifold for the Vortec heads. I'm running a Quadrajet with electric choke and aftermarket HEI that came with a mellonized gear. Your rams horn manifolds will work on the exhaust side. Member A1971Blazer machines the temp sending units and does a really nice job. You do need a flex plate or flywheel.

For the money, I'd go with the factory-new L31 vs the remanufactured.

[72longstepper]

OK TY all for info.

[berudd]

Based on the pic, those aren’t Vortec heads. Vortec heads have 4 intake bolts each and are oriented down. Those heads have 6 intake bolts per head and are angled outward.

[Greasey Harley]

Buying the cheapest engine you can find on the internet, and having it shipped half way across the country, seems like a bad idea to me.
That price point will probably get you a mas produced engine with the cheapest Chinese parts available.
Add to that that you will have to remove it and ship it back to them to deal with any warranty issues.
You would probably be money ahead to pay a little more and buy locally. Looks like you're in the Seattle area?
Here are some local engine manufactures .

https://www.google.com/search?client...E,lf:1,lf_ui:2

I have used Jasper engines several times. They are ok. Their warranty is decent. Their prices are cheap, and they are within driving distance.

Just my $.02

[berudd]

Originally Posted by berudd

Based on the pic, those aren’t Vortec heads. Vortec heads have 4 intake bolts each and are oriented down. Those heads have 6 intake bolts per head and are angled outward.

OK, their is another pic that does have Vortec heads so maybe you can get either.