Hi,
Im all new to the LS-world.

So I bought my first LS-based engine today, a lm7 wich Im gonna build on and put in my impala -65. It's disassembled because the camshaft bearings had worned out. I got 243 heads to go with it, and a 4519 camshaft (ls2). I noticed the bore is bigger on a LS2, so will the heads fit? And also, my goal is close to 400hp, will the cam along with the heads, plus cold air intake and headers do the work? I've looked at this cam https://www.summitracing.com/int/par...make/chevrolet , is that a better choice then the ls2? Any other inputs or ideas?

Thx.

 

An iron LM7 can often be bored out to a total displacement of 5.7 liters if your machinist gives you a thumbs up. Generally, if there was no core shift during casting, there's enough meat in the cylinder bores to machine it out to 5.7 liters. If you have to bore your 5.3, you might as well go to 5.7 if you can. The cost difference is tiny here, if any at all.

Rick

 

LS2, LQ4 and LQ9's come in at a 4.00 inch bore and if boring an LM7 out to 3.898 bore is doable it would work well with your 243's

 

The 243 heads will fit fine. That summit cam would be better. The LS2 cam may be more trouble than its worth. Gen III engines have the cam sensor in the back of the block and read the cam position from a reluctor at the back of the camshaft. Gen IV engines, like the LS2, have the cam position sensor in the front cover so the Gen IV camshafts usually do not have the reluctor on the cam.

 

Thanks for the input, I’ll go for the summit cam. I dont want to bore it, at least not this year. Should I go for ls6 valve springs? Any other lifters and pushing rods?

 

Btw, what oil pan and engine mounts do I need? I cant find any swap parts for gm b-body 65-70.

 

If I was you, I'd go over to the "Conversions & Hybrids" section and search around a little bit. Lots of guys over there with B-body swaps. Good luck.

 

Impala1965,

Thank you for thinking of choosing our SUM-8701 camshaft for your project. This camshaft will provide good mid-range and top-end power. It will also have a slight lope depending on where the idle speed is set. LS6 springs are not required but it would be a good idea to go ahead with new springs since you will have the engine apart for the cam swap. We would recommend to go with the SUM-8701-2-BHV camshaft kit. This will come with the 8701 camshaft, LS6 beehive springs, valve seals, harmonic balancer bolt and gaskets and o-rings to help complete the cam swap. For lifters we would recommend the SUM-HTLSKIT LS7 style lifters and lifter guides.As far as pushrods we would recommend to check for pushrod length once the camshaft is installed with a pushrod length checker and we offer the TFS-9501 to do so.

We see that your also looking for recommendations for an oil pan and motor mounts. For the oil pan we would recommend the SUM-121200 oil pan kit. This includes a new LS swap oil pan, pickup, gasket and hardware. For the motor mounts there are options depending on the stock style mounts you have and the placement of the engine that you would prefer. Follow this link to view the options we have available for you.

 

Interesting reads, thanks.
Is that pan flush to the crossmember? Im putting air ride on it and dont want any troubles regarding the clearance of the pan.

 

While your in there....swap out those pistons for some 4.8 flat tops, with your 243 heads it will be close to gen 4 stats and have a bit more compression, the summit cam is basically the same as a gm hot cam.....I did this very same thing your planning with my lm7 but I went 1 step up with the asa cam...(Summit version ).that motor screams!!!!! Good luck with your decisions....hope to see some pics soon , I've always had a soft spot for the '65 impala! !!!

 

Me too, I've drag raced my '65 Belair for 34 years...

 

What bore should I go for on a stock lm7?

 

A quick hone should be all you need, If you must bore it id just start with a 6.0 block...

 

Yeah I meant what bore size on the pistons. Whats the stock bore size?

 

3.780...=4.8/5.3 depending on stroke
..

 

We cannot confirm if it would be flush to your crossmember but we can show you the dimensions of the pan to give you a visual reference.

 

So I got a new truck camshaft stage 3, some clevite bearings and oil pan from summit yesterday, thanks. I need to replace my cam bearings as well and got a set of them when I bought the engine. I was wondering if they should go in a specific order because they're not the same size, at least two of them is bigger then the rest. Plus I was wondering if I could put them in the freezer to shrink them just before the installation, and maybe heat up the engine block, or do I need a cam bearing installation tool? Thanks.

 

Measure the OD of the bearings. The 2 largest go on the ends, 2 next largest next to those, the smallest in the middle. You work from both ends of the block.
Obviously the ID's are all the same.

 

Thx man

 

So I almost got everything for the engine, I've got the cam bearing tool along with the cam bearings from summit racing today. I've started looking at headers, do you guys think some of this two would fit the 65 B-body?