cookj

Hello all, i'm new to these forums and was looking for some recommendations. My answers may already be in here somewhere but haven't had time to research. I bought this C2500 2WD about 3 months ago with 149K miles; it has the L31, 4L80E and 373 gears. About a month agao, I tried to pull a 5500# Jayco to the lake and this truck wanted no part of it. Long story short, the engine has low compression and i've decided to replace it.

As much as i'd like to upgrade the upper end to achieve better hp/tq, i just don't have the time or money to invest. So, will most likely be sticking with the L31. I've spoken with a number of companies and will most likely go with Jegs. Plans are to purchase a new L31 longblock and convert over to the MFI. I'm also considering the flowtech shorty headers (91832-1), using the factory converters and pipe; the previous owner installed a Magnaflow, dual inlet and single outlet using factory tail pipe.

This truck will be driven daily, and, will tow this Jayco probably 5-7 times a year. Regarding towing with this 5.7, I'm kinda on the fence because of the mixed responses I've heard or read elsewhere. So, my question is, based on my intentions above and considering the 4L80 and 373 gears, shouldn't this combo be more than enough to tow this Jayco, and, in OD on flat roads?

wheeliE-maxx

Shorty headers won't do too much for you. I believe on that truck, you can keep the stock converter location with long tubes. Those and a tune should help a lot.

Whitecrewcab

iTrader: (2)

I would go for a 383 shortblock with the vortec heads. More cubes, more torque and it looks stock. The L31 heads can have minor work done and flow very well for an old school small block.

cookj

thanks for your input. However, i thought the shorties (with 1-1/2" primaries) would be ideal for this application, with tq gains in the low-mid rpm range? surely something better than the cast manifolds.

Sales2@SDPC

iTrader: (9)

Just a heads up that would be a great option is we sale a ht383e that will be a direct replacement for what you have...340hp and 435 torque...And it comes with a 2yr 50,000 mile warranty.. Give me a call and we can talk price 1-800-456-0211 ext353....

cookj

I did very little reading on the stroker motor, but, a couple of places i called said these were designed for 1/2 ton applications with 2-bolt mains. Not that i believed i couldn't go this route, but, after looking at the sticker price for a HT383 E long block (>$5000) I decided not to pursue. Hadn't thought about the short block with worked heads though. Guess i'll need to do some reading on what kind of work would need to be involved with the heads. My goal was really to drop in a L31 with improved intake/exhaust and MFI conversion and be done with it in a weekend. I'm thinking this would yield probably a gain of 15-20hp/25tq over stock. Is this wishful thinking on my part?? thanks

Whitecrewcab

iTrader: (2)

Just simple bowl work, 1.94/1.5 valves if they don't have them already and modifying the guides for bigger lift. If I remember right, GMPP sells the heads with better springs and the guides done for like $525. They went up a bit.

Summit Racing® Vortec Cylinder Heads SUM-151124 - Free Shipping on Orders Over $99 at Summit Racing

cookj

10/4, thank you

1FastBrick

iTrader: (17)

FYI the guys at SDPC can get you the same parts and they are a GM dealer.

They also sponsor this forum.

Your also probably not going to gain much to make it worthwhile though without adding a cam. 20 HP isn't going to help you if it hurt the last engine towing that Jayco.

You might not be able to afford the 383 but it will add the Torque you need to tow that thing around.

The 3.73 are probably not helping you in the towing department either.

cookj

(fastbrick) I don't know the previous owner, but, looking at the gaskets/hardware around the plenum and intake, i'm pretty positive he had a coolant leak and did not correct it in time which has resulted in the issues i'm having today. This truck is clean inside and out, and, for daily driving and long trips (unhooked), will probably be fine for the next 2-3 years. However, we like to camp and have a need to pull this Jayco on occasion.

I spoke with SDPC yesterday and recieved quote on the HT383. To get the full benefits of this motor, i would need to upgrade intake/exhaust and re-tune to come close to those hp/tq #s; this equates to twice the amount of $$ I was expecting to shell out for the L31, MFI and headers. I wish i could go this route, but, unfortunately i can't at this time.

So, my question remains, will a new L31 handle my towing needs? all responses are greatly appreciated. thanks guys.