Jegs crate engine

[Lanman1972]

Anyone use this engine in one of our trucks? $1599, requires external balance flexplate and passenger side dip stick. This is for a basically stock 1971 Cheyenne project.

https://www.jegs.com/i/JEGS/059/7353/10002/-1

Thanks for the input.

[Lanman1972]

Admin sorry for posting twice please delete as needed. My bad.

[sweetk30]

why buy a tiny 195hp engine when a few bucks more get you a lot more . . .

[Lanman1972]

Like what? Your comment was no help at all. If you have knowledge of a better option please share.

[Captainfab]

This long block is the same price and is a far better engine to work with. It has the factory roller cam so no worries about a flat tappet cam going flat. The two drawbacks is that you need a Vortec specific intake manifold and an electric fuel pump.

https://www.jegs.com/i/JEGS/059/0282/10002/-1

[cadillac_al]

I thought the L31 got discontinued . Was that just a internet rumor? I like how the picture shows a fuel pump mount. As much as I don't want an electric fuel pump I think I would still love to have an L31. GM makes a cool little electric pump anyway that should be reliable.

OK now I see, it's not a new GM engine it's a rebuilt one.

[geezer#99]

Yup!
A rebuilt by perhaps one of the worst rebuilders there is.
They have the fuel pump mount but no pushrod hole.

[tdangle]

The L31 is still available from Jegs as a rebuilt engine. Keep in mind if you go that route (which is a good choice) you will need a few things. Intake manifold, bolts for the manifold, different flex plate, depending on the flex plate you choose, new starter, new gear for your diet., coolant bypass, possibly a new harmonic balancer, new timing chain cover as the stock one, not only is a 1 use item, it has the hole for a crank sensor. If you have stock AC, the rear support won't work on the new manifold. Depending on what you want to reuse and what you have to add new, figure and extra ~$1000. I know if sounds like a lot, but I just went thru it and could not believe all the extra costs and I bought a new GM crate motor SP350/357 deluxe which included flex plate, manifold, balancer and carb. Still ended up spending a LOT extra (about 1500 including tuning)

[68c10owner]

I have this engine in my 79. It seems ok for a driver. I didnt realize they were 1 PC seal blocks so just use a flex plate from a 87-up 1 PC seal. Most afternarketnones will be dual drilled for different converters

[Ironangel]

JEGS still has this L31 for the same money. https://www.jegs.com/i/JEGS/059/0282/10002/-1 I just installed their 260hp flat tappet motor in one of my 72's and it runs great but don't have the power the L31 has. I bought my motor 5 years ago when they were $1200 delivered. The (rebuilt) L31 is a steal at $1599 for couple of reasons, it comes with a 36 month warrantee and you cant even buy the parts for that price. The L31 requires an electric fuel pump and the Vortec intake manifold, $300 for 100 extra pony's with better mileage and any off the shelf motor oil...Your call.

[toolboxchev]

Yea, just looked again at the L31 HD motor. Had a question for some in the know.

Static comp is 9.4 to 1, anyone know the dynamic compression ratio is on that motor? I am assuming is low.

[68c10owner]

Originally Posted by toolboxchev

Yea, just looked again at the L31 HD motor. Had a question for some in the know.

Static comp is 9.4 to 1, anyone know the dynamic compression ratio is on that motor? I am assuming is low.

Would depend on the cam specs. Im sure someone will know where to find those. My old vortec 305 and 350 both ran fine on 87 octane gas so its not super high.

[truckster]

Here's a calculator you can use.

http://wallaceracing.com/dynamic-cr.php

I put the HT 383 cam in mine for more torque. With that cam, it puts out roughly 330 HP and 400 lb-ft of torque. With the HT383 cam this calculator puts the dynamic compression ratio at 9.16:1.